| | Event type
Middleweight (≤86 kilograms), Men
| Date | 8 August 1984 — 16:00-20:00 | |
|---|---|---|
| Status | Olympic | |
| Location | Eagle's Nest Arena, California State University at Los Angeles, Los Angeles, California | |
| Participants | 29 from 29 countries | |
| Format | Two single-elimination pools, with winner of each pool advanced to the final. All judoka losing to the winner of each pool advanced to repêchage pools, with the winners of the repêchage pools earning bronze medals. | |
The 1983 World Champion was Detlef Ultsch (GDR), while earlier in 1984, Soviet Vitaly Pesnyak had defeated East German Michael Borawski for the European title. Because of the boycott, none of them were in Los Angeles. But the other three medalists from the 1983 Worlds were present – Bob Berland (USA), Fabien Canu (FRA), and Japan’s Seiki Nose. Nose was a 6th Dan, the highest grade in the 1984 judo tournament. In the end, one judoka dominated the class, but it was not a favorite. Peter Seisenbacher, an Austrian goldsmith, won all five of his matches before the time limit, taking 11:05 to win his gold medal. In the final he fought Berland, winning by ippon with ashi-guruma in 2:26.
Pool A (8 August 1984)
Round One (8 August 1984)
| Match #1 | Chang Shou-Chung |  TPE | Ippon/Uchi-mata (2:44) | Séraphin Okuaka |  CGO |
| Match #2 | Peter Seisenbacher |  AUT | Waza-ari-wasete Ippon/O-uchi-gari/kesa-gatame | Stanko Lopatić |  YUG |
| Match #3 | Eduardo Novoa |  CHI | Ippon/Seoi-nage (0:23) | Hussain Shareef |  KUW |
| Match #4 | Seiki Nose |  JPN | Ippon/Uchi-mata (0:07) | Kostas Papakostas |  CYP |
| Match #5 | Marc Meiling |  FRG | Yusei-gachi [2/3] (5:00) | Louis Jani |  CAN |
| Match #6 | Fabien Canu |  FRA | Yuko/O-uchi-gari (5:00) | Clément Nzali |  CMR |
| Match #7 | Park Gyeong-Ho |  KOR | Waza-ari/O-soto-gari (5:00) | Andrew Richardson |  AUS |
| Match #8 | Bill Vincent |  NZL | Ippon/Kansetsu-juji-gatame (3:33) | Alejandro Strático |  ARG |
Quarter-Finals (8 August 1984)
| Match #1 | Peter Seisenbacher | AUT | Ippon/Kansetsu-juji-gatame (0:45) | Chang Shou-Chung | TPE |
| Match #2 | Seiki Nose | JPN | Ippon/Uchi-mata (0:28) | Eduardo Novoa | CHI |
| Match #3 | Fabien Canu | FRA | Ippon/Kaeshi-waza (2:32) | Marc Meiling | FRG |
| Match #4 | Park Gyeong-Ho | KOR | Ippon/Harai-goshi (2:43) | Bill Vincent | NZL |
Semi-Finals (8 August 1984)
| Match #1 | Peter Seisenbacher | AUT | Ippon/Kusure-kami-shiho-gatame (4:23) | Seiki Nose | JPN |
| Match #2 | Fabien Canu | FRA | Yuko/Kaeshi-waza (5:00) | Park Gyeong-Ho | KOR |
Final Round (8 August 1984)
| Match #1 | Peter Seisenbacher | AUT | Ippon/Kansetsu-juji-gatame (2:01) | Fabien Canu | FRA |
Repêchage (8 August 1984)
| Match #1 | Stanko Lopatić | YUG | Koka-shido (5:00) | Chang Shou-Chung | TPE |
| Match #2 | Seiki Nose | JPN | Ippon/O-soto-gari (0:34) | Stanko Lopatić | YUG |
| Match 3/4 | Seiki Nose | JPN | Ippon/Shime-waza (2:12) | Fabien Canu | FRA |
Pool B (8 August 1984)
Round One (8 August 1984)
| Match #1 | Densign White |  GBR | Waza-ari-wasete Ippon/Seoi-nage/Kusure-kesa-gatame (2:36) | Eric-Louis Bessi |  MON |
| Match #2 | Alfonso García |  ESP | Hansoku-make (4:38) | Mario Vecchi |  ITA |
| Match #3 | Bob Berland |  USA | bye | ||
| Match #4 | Magnus Büchel |  LIE | Yuko/Moro-te-gari (5:00) | Franch Casadei |  SMR |
| Match #5 | Ben Spijkers |  NED | bye | ||
| Match #6 | Hamza Doublali |  MAR | Yusei-gachi [2/3] (5:00) | José Fuentes |  PUR |
| Match #7 | Wálter Carmona |  BRA | Ippon/O-uchi-gari (1:08) | Atif Muhammad Hussain |  EGY |
Quarter-Finals (8 August 1984)
| Match #1 | Densign White | GBR | Ippon/Seoi-nage (3:22) | Alfonso García | ESP |
| Match #2 | Bob Berland | USA | Ippon/Uchi-mata (1:09) | Magnus Büchel | LIE |
| Match #3 | Ben Spijkers | NED | Ippon/Kusure-yoko-shiho-gatame (2:57) | Hamza Doublali | MAR |
| Match #4 | Wálter Carmona | BRA | Ippon/Tai-otoshi (2:37) | Michel Grant |  SWE |
Semi-Finals (8 August 1984)
| Match #1 | Bob Berland | USA | Yusei-gachi [3/3] (5:00) | Densign White | GBR |
| Match #2 | Wálter Carmona | BRA | Yusei-gachi [3/3] (5:00) | Ben Spijkers | NED |
Final Round (8 August 1984)
| Match #1 | Bob Berland | USA | Yuko/O-uchi-gari (5:00) | Wálter Carmona | BRA |
Repêchage (8 August 1984)
| Match #1 | Densign White | GBR | Ippon/Seoi-nage (1:18) | Magnus Büchel | LIE |
| Match 3/4 | Wálter Carmona | BRA | Yuko/O-uchi-gari (7:00) | Densign White | GBR |
Final Round (8 August 1984)
| Match 1/2 | Peter Seisenbacher | AUT | Ippon/Uchi-mata (2:26) | Bob Berland | USA |