• IMO held in Madrid, Spain
• 535 Participants from 101 countries
• There were 47 gold medals, 100 silver medals, and 120 bronze medals

• IMO held in Hanoi, Vietnam
• 536 Participants from 94 countries
• There were 39 gold medals, 83 silver medals, and 131 bronze medals

• IMO held in Ljubljana, Slovenia
• 498 Participants from 90 countries
• There were 42 gold medals, 89 silver medals, 122 bronze medals and 139 Honorable Mention

• IMO was held in Merida, Mexico
• 517 participants from 91 countries
• There were 42 gold medals, 79 silver medals, 125 bronze medals, and 66 Honorable Mention

• IMO was held in Athens Greece
• The Contest had participants from 85 countries
• There were 45 gold medals, 78 silver medals, and 120 bronze medals

• IMO was held in Tokyo, Japan
• The Contest had participants of 457 students from 82 countries + 2 countries with observer participants only
• There were 35 Gold Medals, 66 Silver Medals and 100 Bronze Medals

• IMO was held in Glasgow, Scotland, UK,
• 84 countries participating
• 39 Gold medals, 73 silver and 120 bronze medals awarded

• IMO was held in Washington, DC, USA.
• 83 countries participating.

• IMO was held in Taejon, Korea.
• 82 countries were represented.
• To commemorate the event, Korea issued a postage stamp.
• There were 39 gold medals, 71 silver medals, and 119 bronze medals awarded.
• All six representatives for China earned gold medals: Zhiwei Yun, Zhipeng Liu, Xin Li, Qihui Zhu, Xinyi Yuan, and Zhongtao Wu.
• Top scorers were Alexandr Usnich (Belarus), Zhiwei Yun (China), Alexei Poiarkov (Russia), and Alexandre Gaifoulline (Russia). Each had 42 points, a perfect score.
• Kentaro Nagao earned his third gold medal for Japan.
• Vladimir Dremov earned his third gold medal for Russia.
• Reid Barton earned his third gold medal for the U.S. He will be returning in 2001

• IMO was held in Bucharest, Romania.
• 81 countries were represented.
• There were 38 gold medals, 70 silver medals, and 118 bronze medals awarded.
• Romania became the first country to host IMO five times.
• Top scorers were Tamás Terpai (Hungary), Stefan Laurentiu Hornet (Romania), and Maksym Fedorchuk (Ukraine), who earned 39 points each.
• Tamás Terpai earned his third gold medal for Hungary.
• Geoffrey Chu became the first Australian contestant to win a gold medal.
• Raja Mukherji became first contestant to win two medals in a row for Ireland.

• IMO was held in Taipei, Taiwan.
• 76 countries were represented.
• There were 37 gold medals, 67 silver medals, and 102 bronze medals awarded.
• Top scorer was Omid Amini (Iran) with a perfect score of 42.
• Melanie Wood became the first female representing the United States. She earned a silver medal and was the subject of an article in Discover magazine.
• Nikolai Dourov earned his third gold medal for Russia.
• Ivan Ivanov earned his third gold medal for Bulgaria.
• William Ted Blackwell II earned a bronze medal, becoming the first medalist for Trinidad and Tobago.
• Oscar Felipe Bernal Pedraza earned the first gold medal for Colombia.

• IMO was held in Mar del Plata, Argentina.
• 82 countries were represented.
• There were 39 gold medals, 70 silver medals, and 122 bronze medals awarded.
• Top scorers were Carl Bosley (USA), Do Quoc Anh (Vietnam), Eaman Eftekhari (Iran), and Ciprian Manolescu (Romania), each with perfect scores of 42.
• Ciprian Manolescu earned his third gold medal for Romania.
• Bruce Merry became the first South African and the second African to win a gold medal. He appeared at IMO five times and medaled four of those times.
• Sachiko Nakajima became the first female representing Japan to win a gold medal.

• IMO was held in Mumbai, India.
• 75 countries were represented.
• Top scorer was Ciprian Manolesco (Romania), who earned a perfect score of 42.
• Sachiko Nakajima became the first female contestant to represent Japan.
• Yulij Samikov earned his third gold medal for the Ukraine.

• IMO was held in North York, Canada.
• 73 countries were represented.
• An amazing number of participants had perfect scores: Nikolay Nikolov (Bulgaria), Song Liu (China), Cheng Chang (China), Chenchang Zhu (China), Mihaly Barasz (Hungary), Peter Burcsi (Hungary), Egmont Koblinger (Hungary), Maryam Mirzakhani (Iran), Sug-woo Shin (South Korea), Dragos Oprea (Romania), Ciprian Manolesco (Romania), Ovidiu Savin (Romania), Serguei Norine (Russia), and Ngo Dac Tuan (Vietnam).
• There were three countries that were represented by three perfect scorers each: China, Romania, and Hungary.
• Nikolai Nikolov earned his third gold medal for Bulgaria.
• Lukito Muliadi became the first person to earn a medal for Indonesia.

• IMO was held in Hong Kong.
• 69 countries were represented.
• There were 30 gold medals, 63 silver medals, and 102 bronze medals awarded.
• For the first time ever in IMO history, all the members of a national team scored a perfect 42, earning them each a gold medal. This team was from the USA and consisted of Jeremy Bem, Aleksandr Khazanov, Jacob Lurie, Noam Shazeer, Stephen Wang, and Jonathan Weinstein. Their achievement was featured in TIME magazine.
• Oleg Alexandrov earned a bronze medal and became the first Moldavian medalist.
• Nasko Karamanov became the first Macedonian competitor to win a silver medal.

• IMO was held in Istanbul, Turkey.
• 73 countries were represented.
• Macedonia first competed, with a reduced team of only four members. Nevertheless, this team earned three bronze medals.
• Moldavia competed for the first time.

• IMO was held in Moscow, U.S.S.R.
• 56 countries were represented.
• South Africa competed for the first time.

• IMO was held in Sigtuna, Sweden.
• 55 countries were represented.
• Theodor Banica earned his third gold medal for Romania.
• Trinidad and Tobago competed for the first time.
• Evgenija Malinnikova earned her third gold medal for the U.S.S.R. She is the only female competitor to have earned three gold medals.

• IMO was held in Beijing, China.
• 54 countries were represented.
• Andrew McMurry became the first person to win a medal for Ireland.

• IMO was held in Brunswick, Germany.
• 52 countries were represented.
• Ngo Bau Chau became the first contestant to earn two consecutive gold medals for Vietnam.
• Martin Harterich made his fifth appearance at IMO. In total he earned three gold medals, one silver medal, and one bronze medal for what was then West Germany.
• Sergej Ivanov earned his third gold medal for the U.S.S.R.

• IMO was held in Canberra, Australia.
• 49 countries were represented.
• David Wallace became the first person to win a silver medal for New Zealand.
• This was the first time IMO was held in the Southern Hemisphere.
• Ireland competed for the first time.

• IMO was held in Havana, Cuba.
• 42 countries were represented.

• IMO was held in Warsaw, Poland.
• 37 countries were represented.

• IMO was held in Joutsa, Finland.
• 38 countries were represented.

• IMO was held in Prague, Czechoslovakia.
• 34 countries were represented.

• IMO was held in Paris, France.
• 32 countries were represented.

• IMO was held in Budapest, Hungary.
• 30 countries were represented.

• IMO was held in Washington, DC, USA.
• 27 countries were represented.
• Timothy Gowers earned a gold medal for the UK. He would go on to win the Fields Medal in 1998.
• Canada competed for the first time.
• The USA hosted IMO for the first time.

• IMO was not held.

• IMO was held in London, UK.
• 23 countries were represented.
• Alexander Razborov earned a gold medal for the U.S.S.R. He would go on to win the Nevanlinna Prize in 1990.

• IMO was held in Bucharest, Romania.
• 17 countries were represented.

• IMO was held in Belgrade, Yugoslavia.
• 20 countries were represented.
• Richard Borcherds earned a silver medal for the UK. He would go on to win the Fields Medal in 1998.
• Peter Shor earned a silver medal for the USA. He would go on to win the Nevanlinna Prize in 1998.

• IMO was held in Linz, Austria.
• 19 countries were represented.

• IMO was held in Burgas, Bulgaria.
• 17 countries were represented.

• IMO was held in Berlin, East Germany.
• 16 countries were represented.
• Jean-Christof Yoccoz earned a gold medal for France. He would go on to win the Fields Medal in 1994.
• The USA competed for the first time.

• IMO was held in Moscow, U.S.S.R.
• 16 countries were represented.

• IMO was held in Torun, Poland.
• 15 countries were represented.

• IMO was held in Zilina, Czechoslovakia.
• 15 countries were represented.
• Wolfgang Burmeister made his fifth appearance at IMO. In total, he earned three gold medals and two silver medals for what was then East Germany.

• IMO was held in Keszthely, Hungary.
• 14 countries were represented.

• IMO was held in Bucharest, Romania.
• 14 countries were represented.
• Simon Norton became the first person to win three consecutive gold medals for the UK.
• Vladimir Drinfel'd earned a gold medal for the Soviet Union. He would go on to earn the Fields Medal in 1990.

• IMO was held in Moscow, U.S.S.R.
• Nine countries were represented.

• IMO was held in Cetinje, Yugoslavia.
• 13 countries were represented.
• Simon Norton earned a gold medal for the UK in its first competition.

• IMO was held in Sofia, Bulgaria.
• Nine countries were represented.
• Laszlo Lovasz and Jozsef Pelikan appeared for the fourth time at IMO. Each of them won a total of three gold medals and one silver medal for Hungary in four appearances.

• IMO was held in Berlin, East Germany.
• 10 countries were represented.

• IMO was held in Moscow, U.S.S.R.
• Nine countries were represented.

• IMO was held in Wroclaw, Poland.
• Eight countries were represented.

• IMO was held in Czechoslovakia.
• Seven countries were represented.
• For this year alone, there were seven questions instead of six.
• Grigorig Margulis earned a silver medal for the U.S.S.R. He would go on to win the Fields Medal in 1983.

• IMO was held in Hungary.
• Six countries were represented.

• IMO was held in Bucharest, Romania.
• Five countries were represented.

• IMO was held in Bucharest, Romania.
• Seven countries were represented.
• This was the first IMO.

Note: From 1974 through 1981 a team consisted of 8 members. In 1982 a team consisted of 4 members. From 1983 to the present a team has consisted of 6 members.

1959-2001 courtesy of http://imo.wolfram.com