# Swimming at the 1984 Summer Olympics – Men's 400 metre individual medley

The final of the men's 400 metre individual medley event at the 1984 Summer Olympics was held in the McDonald's Olympic Swim Stadium in Los Angeles, California, on July 30, 1984. 24 athletes participated in the heats, with the fastest eight qualifying for the final.

## Records

Prior to this competition, the existing world and Olympic records were as follows.
| World record | Alex Baumann (CAN) | 4:17.53 | Etobicoke, Canada | 17 June 1984 |
| Olympic record | Aleksandr Sidorenko (URS) | 4:22.89 | Moscow, Soviet Union | 27 July 1980 |
The following records were established during the competition:
| Date | Round | Name | Nation | Time | Record |
| 30 July | Heat 3 | Alex Baumann | Canada | 4:22.46 | OR |
| 30 July | Final A | Alex Baumann | Canada | 4:17.41 | WR |

## Results
### Heats

Rule: The eight fastest swimmers advance to final A (Q), while the next eight to final B (q).
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 3 | 4 | Alex Baumann | Canada | 4:22.46 | Q, OR |
| 2 | 3 | 5 | Jeff Kostoff | United States | 4:22.55 | Q |
| 3 | 1 | 4 | Giovanni Franceschi | Italy | 4:23.03 | Q |
| 4 | 2 | 4 | Ricardo Prado | Brazil | 4:23.31 | Q |
| 5 | 1 | 5 | Maurizio Divano | Italy | 4:23.61 | Q |
| 6 | 2 | 5 | Jesse Vassallo | United States | 4:23.82 | Q |
| 7 | 3 | 3 | Rob Woodhouse | Australia | 4:24.85 | Q, OC |
| 8 | 3 | 6 | Stephen Poulter | Great Britain | 4:25.38 | Q, NR |
| 9 | 2 | 3 | Ralf Diegel | West Germany | 4:28.10 | q |
| 10 | 2 | 6 | Arne Borgstrøm | Norway | 4:28.37 | q |
| 11 | 2 | 7 | Andrew Phillips | Jamaica | 4:29.43 | q, NR |
| 12 | 1 | 3 | Peter Dobson | Canada | 4:29.61 | q |
| 13 | 1 | 2 | Shinji Ito | Japan | 4:30.52 | q |
| 14 | 1 | 6 | Stuart Willmott | Great Britain | 4:32.90 | q |
| 15 | 2 | 2 | Anders Peterson | Sweden | 4:32.93 | q |
| 16 | 3 | 7 | Yoram Kochavy | Israel | 4:35.70 | q, NR |
| 17 | 1 | 7 | Scott Newkirk | Virgin Islands | 4:48.15 | |
| 18 | 2 | 1 | Jairulla Jaitulla | Philippines | 4:51.24 | |
| 19 | 3 | 1 | Harry Wozniak | Barbados | 4:53.87 | |
| 20 | 1 | 1 | Ng Wing Hon | Hong Kong | 4:58.98 | |
| 21 | 2 | 8 | Julian Bolling | Sri Lanka | 5:02.88 | |
| 22 | 3 | 8 | Wu Ming Hsun | Hong Kong | 5:02.94 | |
| 23 | 1 | 8 | Juan José Piro | Honduras | 5:15.68 | |
| | 3 | 2 | Rafael Escalas | Spain | DNS | |

### Finals
#### Final B

| Rank | Lane | Name | Nationality | Time | Notes |
| 9 | 1 | Anders Peterson | Sweden | 4:27.95 | NR |
| 10 | 3 | Andrew Phillips | Jamaica | 4:27.98 | NR |
| 11 | 5 | Arne Borgstrøm | Norway | 4:28.20 | |
| 12 | 4 | Ralf Diegel | West Germany | 4:28.94 | |
| 13 | 2 | Shinji Ito | Japan | 4:29.76 | AS |
| 14 | 6 | Peter Dobson | Canada | 4:30.09 | |
| 15 | 7 | Stuart Willmott | Great Britain | 4:31.10 | |
| 16 | 8 | Yoram Kochavy | Israel | 4:40.00 | |

#### Final A

| Rank | Lane | Name | Nationality | Time | Notes |
| | 4 | Alex Baumann | Canada | 4:17.41 | WR |
| | 6 | Ricardo Prado | Brazil | 4:18.45 | SA |
| | 1 | Rob Woodhouse | Australia | 4:20.50 | OC |
| 4 | 7 | Jesse Vassallo | United States | 4:21.46 | |
| 5 | 2 | Maurizio Divano | Italy | 4:22.76 | |
| 6 | 5 | Jeff Kostoff | United States | 4:23.28 | |
| 7 | 8 | Stephen Poulter | Great Britain | 4:25.80 | |
| 8 | 3 | Giovanni Franceschi | Italy | 4:26.05 | |