Athiaporn Koonjarthong was a member of the Thai 4×400 m Olympic team in 1992, with a best time of 47,93. Three years later he was in the team that was disqualified in heat at the Asian Championship.
Personal Best: 400 – 47.78 (1994).
| Games | Discipline (Sport) / Event | NOC / Team | Pos | Medal | As | |
|---|---|---|---|---|---|---|
| 1992 Summer Olympics | Athletics |  THA |
Athiaporn Koonjarthong | |||
| 4 × 400 metres Relay, Men (Olympic) | Thailand | 6 h1 r1/2 |
