| 35 from 25 nations|
| 4:14.75 WR|
| Jamsil Indoor Swimming Pool|
Jamsil Indoor Swimming Pool, Songpa District, South Korea
The men's 400 metre individual medley event at the 1988 Summer Olympics took place between 20–21 September at the Jamsil Indoor Swimming Pool in Seoul, South Korea.
Swimming at the 1988 Summer Olympics – Men's 400 metre individual medley Wikipedia
Prior to this competition, the existing world and Olympic records were as follows.
The following records were established during the competition:
Rule: The eight fastest swimmers advance to final A (Q), while the next eight to final B (q).