[4]
Between 1975 and 1991, the World Open Tournament was organized by IKO (International Karate Organization Kyokushinkaikan), led by Mas Oyama. The event was held five times:
- 1st World Open Tournament (1–3 November 1975) with 128 competitors from 32 countries
- 2nd World Open Tournament (23–25 November 1979) with 187 competitors from 62 countries
- 3rd World Open Tournament (20–22 January 1984) with 192 competitors from 60 countries
- 4th World Open Tournament (6–8 November 1987) with 207 competitors from 77 countries
- 5th World Open Tournament (2–4 November 1991) with 250 competitors from 105 countries
| Place | 1st World Open | 2nd World Open | 3rd World Open | 4th World Open | 5th World Open |
| 1 | Katsuaki Satō  | Makoto Nakamura | Makoto Nakamura  | Akiyoshi Matsui  | Kenji Midori  |
| 2 | Hatsuo Royama  | Keiji Sanpei  | Keiji Sanpei  | Andy Hug  | Akira Masuda  |
| 3 | Joko Nimoniya  | Willie Williams  | Akiyoshi Matsui  | Akira Masuda | Hiroki Kurosawa |
| 4 | Daigo Oishi  | Takashi Azuma  | Ademir Da Costa  | Michael Thompson  | Jean Riviere |
| 5 | Toshikazu Sato  | Howard Collins  | Yasuto Onishi  | Ademir Da Costa  | Kenji Yamaki  |
| 6 | Takashi Azuma  | Bernard Creton  | Nicholas Da Costa  | Hiroki Kurosawa | Yutaka Ishii |
| 7 | Charles W. Martin  | Ceno Maxer  | Keizo Tahara  | Yasuhiro Shichinohe  | Yasuhiro Shichinohe  |
| 8 | Frank Clark  | Koichi Kawabata  | Dave Greaves  | Nicholas Da Costa  | Johnny Kleyn  |
After the death of Mas Oyama in 1994, IKO split up into several factions. The World Open Tournament has continued to be held but organised in parallel by several organizations.
From 1995, the World Open Tournament has been organized by IKO1[5] led by Shokei Matsui.
- 6th World Open Tournament IKO1 (3–5 November 1995) with 168 competitors from 85 countries
- 7th World Open Tournament IKO1 (5–7 November 1999) with 192 competitors from 86 countries
- 8th World Open Tournament IKO1 (1–3 November 2003) with 240 competitors from 63 countries
- 9th World Open Tournament IKO1 (16–18 November 2007) with 192 competitors from 65 countries
- 10th World Open Tournament IKO1 (4–6 November 2011) with 192 competitors from 43 countries
- 11th World Open Tournament IKO1 (20–22 November 2015) with 192 competitors from 46 countries
- 12th World Open Tournament IKO1 (22–24 November 2019) with 164 competitors from 38 countries
- 13th World Open Tournament IKO1 (17–19 November 2023) with 166 competitors from 35 countries
From 1996, the World Open Tournament has also been organized by WKO (World Karate Organization Shinkyokushinkai)[6] led by Kenji Midori.
- 6th World Open Tournament WKO (February 1996) with 172 competitors
- 7th World Open Tournament WKO (5–6 December 1999) with 128 competitors from 53 countries
- 8th World Open Tournament WKO (4–5 October 2003) with 128 competitors from 63 countries
- 9th World Open Tournament WKO (13–14 October 2007) with 128 competitors
- 10th World Open Tournament WKO (4–6 November 2011) with 129 competitors from 52 countries
- 11th World Open Tournament WKO (31 October – 1 November 2015) with 164 competitors from 60 countries
- 12th World Open Tournament WKO (9–10 November 2019) with 161 competitors from 71 countries
- 13th World Open Tournament WKO (14–15 October 2023)
| Place | 6th World Open | 7th World Open | 8th World Open | 9th World Open | 10th World Open | 11th World Open | 12th World Open | 13th World Open |
| 1 | Norichika Tsukamoto  | Toru Okamoto  | Kunihiro Suzuki  | Takayuki Tsukagoshi  | Norichika Tsukamoto  | Yuji Shimamoto  | Yuji Shimamoto  | Kembu Iriki  |
| 2 | Kunihiro Suzuki  | Muzaffer Bacak  | Yuichiro Osaka  | Donatas Imbras  | Tsutomo Muruyama  | Kembu Iriki  | Maciej Mazur  | Valeri Dimitrov  |
| 3 | Kou Tanigawa  | Sotoshi Niiho  | Takayuki Tsukakoshi  | Valeri Dimitrov  | Roman Nesterenko  | Lukas Kubilius  | Daiki Kato  | Edgard Secinski  |
| 4 | Tsuyoshi Murase  | Kouji Abiko  | Valeri Dimitrov  | Roman Nesterenko  | Lukas Kubilius  | Shota Maeda | Valeri Dimitrov  | Anton Zimarev  |
| 5 | Akira Masuda  | Kunihiro Suzuki | Francisco Jose Carpena  | Maxim Shevchenko  | Brian Jakobsen  | Kazufumi Shimamoto  | Kosei Ochiai | Kosei Ochiai  |
| 6 | Hiroyuki Miake  | Tadashi Ishihara  | Muzaffer Bacak  | Darius Gudauskas  | Andrey Materov  | Nazar Nasirov  | Eventas Guzauskas  | Yuki Okada  |
| 7 | Toru Okamoto  | Yuichiro Osaka  | Norichika Tsukamoto  | Norichika Tsukamoto  | Yuji Shimamoto | Edgard Sečinski  | Yuto Eguchi | Ryuji Toda  |
| 8 | Kouji Abiko  | Viktor Karasyuk  | Daniel Torok  | Denis Grigoriev  | Yevgeniy Andrushko  | Maciej Mazur  | Ilya Yakovlev  | Yusaku Watanabe |
From 2000, the World Open Tournament has also been organized by IKO3[7] led by Yoshikazu Matsushima [ja].
- 6th World Open Tournament IKO3 - Not held, info needed?
- 7th World Open Tournament IKO3 (25-26 November 2000, Tokyo, Japan)
- 8th World Open Tournament IKO3 (27-28 November 2004, Isesaki City, Japan)
- 9th World Open Tournament IKO3 (29-30 November 2008, Isesaki City, Japan)
- 10th World Open Tournament IKO3 (23-24 June 2012, Tokyo, Japan)
- 11th World Open Tournament IKO3 (26-27 November 2016, Maebashi, Japan)
- 12th World Open Tournament IKO3 (22-24, November 2019, Tokyo, Japan)[8]
| Place | 6th World Open | 7th World Open | 8th World Open | 9th World Open | 10th World Open | 11th World Open | 12th World Open |
| 1 | ? | Thorsten Domke  | Hadi Azikhani  | Anzor Shikhabakhov  | Reza Goodary  | Ali Orace  | Mikio Ueda  |
| 2 | ? | Bela Haszmann  | Hassan Nazemi  | Issa Parvari  | Artur Tilov  | Sajjad Mohajeri  | Aleksandr Eremenko  |
| 3 | ? | Raoul Strikker  | Arash Sharifi  | Sajad Heidari | Aleksander Karshigeev  | Denis Morozevich  | Andrei Luzin  |
| 4 | ? | Igor Struikhim  | Haidar Mohammed  | Sergey Doronin  | Aleksander Ibragimov  | Mehrdad Ramzani  | Yuta Takahashi  |
| 5 | ? | Alexander Sitnikov  | Andrey Noskov  | Rasim Samedov  | Amin Azimi  | Mdliduzi Mseleku | Konstantin Kovalenko  |
| 6 | ? | Diego Beltran  | Anatoly Boronnikov  | Saeid Sefari  | Naser Karami  | Denys Maxymov  | Ryunosuke Hoshi  |
| 7 | ? | Yevgeny Pechenin  | Eissa Oghani  | Gia Gvenetadze  | Sajjad Heidarinaghdali  | Thondwaylakosi Ndlovu | Igor Zagainov |
| 8 | ? | Kiko Muira | Alexander Ibragimov  | Laszlo Hacsko  | Amir Reza Moradian  | Reza Goodary  | Shoki Arata  |
From 2004, the World Open Tournament has also been organized by All Japan Kyokushin Union (Kyokushin Rengōkai)[9] led by Yasuhiro Shichinohe [ja].
- 1st World Open Tournament Rengōkai (18 January 2004, Shizuoka, Japan)
- 2nd World Open Tournament Rengōkai (19–20 January, Japan, 2008) - held in weight categories
- 3rd World Open Tournament Rengōkai (10–11 November, Toyama, Japan, 2012)
- 4th World Open Tournament Rengōkai (20–21 January, Toyama, Japan, 2017)
They decided though to renumber the event starting with World Open Tournament 1. Also note that the second event in 2008 was organized in weight categories and is therefore not presented here.[10]
| Place | 1st World Open | 2nd World Open | 3rd World Open | 4th World Open |
| 1 | Masaake Shimajiri  | several | Takuma Koketsu  | Yuya Nagata  |
| 2 | Anzor Shikhabakhov  | several | Jonathan Tineo  | Timur Raiymbekov  |
| 3 | Alexander Ibragiumov  | several | Kevin Wiklund  | Yudai Ishimine  |
| 4 | Jiri Onoue  | several | Yuhei Ashitaka  | Shi Shigematsu  |
| 5 | Hiroshi Sugiyama  | several | Akihito Teruya  | Yasumichi Kikuyama  |
| 6 | Yasumichi Kikuyama  | several | Jonathan Redondo  | Akihito Teruya  |
| 7 | Takeshi Miyagi  | several | Masaru Sato  | Kim Jong Kil  |
| 8 | Timofei Tsyganov  | several | Syota Yamaguchi  | Yuhei Ashitaka  |
Results to be added