The men's decathlon event at the 1988 World Junior Championships in Athletics was held in Sudbury, Ontario, Canada, at Laurentian University Stadium on 27 and 28 July. Senior implements (106.7 cm (3'6) hurdles, 7257g shot, 2 kg discus) were used.
| Gold | Michael Kohnle | |
| Silver | Robert Změlík | |
| Bronze | Eduard Hämäläinen |
27/28 July
| Rank | Name | Nationality | 100m | LJ | SP | HJ | 400m | 110m H | DT | PV | JT | 1500m | Points | Notes | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| align=left | align=left | 10.78 (w: 0.8 m/s) | 6.97 | 13.25 | 2.01 | 48.98 | 14.60 (w: 0.6 m/s) | 36.50 | 4.50 | 58.38 | 4:38.65 | 7729 | |||||
| align=left | align=left | 11.08 (w: -1.3 m/s) | 7.29 | 12.33 | 2.07 | 51.08 | 14.61 (w: 0.6 m/s) | 38.98 | 4.50 | 56.08 | 4:37.78 | 7659 | |||||
| align=left | align=left | 11.42 | 6.99 | 13.57 | 2.01 | 50.21 | 14.91 | 39.64 | 4.70 | 53.18 | 4:33.22 | 7596 | |||||
| 4 | align=left | align=left |  | 10.85 | 7.00 | 12.08 | 1.92 | 47.90 | 15.20 | 36.08 | 4.30 | 61.40 | 4:50.03 | 7453 | |||
| 5 | align=left | align=left | 11.06 | 6.70 | 12.45 | 1.86 | 49.20 | 15.40 | 41.12 | 4.30 | 53.30 | 4:25.47 | 7359 | ||||
| 6 | align=left | align=left | 11.04 | 6.77 | 12.26 | 2.01 | 50.04 | 15.39 | 36.22 | 4.20 | 50.46 | 4:34.64 | 7233 | ||||
| 7 | align=left | align=left |  | 11.55 | 6.98 | 10.84 | 1.92 | 50.41 | 15.35 | 36.12 | 4.20 | 47.82 | 4:17.96 | 7063 | |||
| 8 | align=left | align=left | 11.65 | 6.56 | 14.19 | 1.83 | 51.54 | 15.29 | 41.92 | 4.30 | 49.20 | 4:44.93 | 7018 | ||||
| 9 | align=left | align=left | 11.18 | 6.78 | 12.74 | 1.86 | 48.77 | 16.56 | 33.22 | 4.10 | 46.52 | 4:19.30 | 6982 | ||||
| 10 | align=left | align=left |  | 11.47 | 7.26 | 10.57 | 1.89 | 53.01 | 16.68 | 35.28 | 4.70 | 56.62 | 4:42.70 | 6937 | |||
| 11 | align=left | align=left |  | 11.10 | 6.42 | 12.68 | 1.95 | 49.12 | 15.53 | 40.84 | 3.60 | 47.50 | 4:54.62 | 6900 | |||
| 12 | align=left | align=left | 11.65 | 6.71 | 11.62 | 1.83 | 51.17 | 15.78 | 36.50 | 4.50 | 49.68 | 4:33.26 | 6883 | ||||
| 13 | align=left | align=left | 11.41 | 7.03 | 11.62 | 1.92 | 51.05 | 15.37 | 36.00 | 4.30 | 41.22 | 4:50.89 | 6837 | ||||
| 14 | align=left | align=left |  | 11.46 | 6.45 | 12.98 | 1.77 | 51.36 | 15.76 | 40.78 | 4.20 | 50.30 | 4:42.94 | 6836 | |||
| 15 | align=left | align=left |  | 11.77 | 6.69 | 10.99 | 2.01 | 52.46 | 16.34 | 33.40 | 4.30 | 54.94 | 4:46.84 | 6729 | |||
| 16 | align=left | align=left | 12.03 | 6.10 | 11.94 | 1.74 | 53.45 | 16.99 | 36.34 | 4.70 | 55.30 | 4:47.98 | 6429 | ||||
| 17 | align=left | align=left | | 11.40 | 6.59 | 10.41 | 1.86 | 49.38 | 16.47 | 30.68 | 3.80 | 35.58 | 4:41.88 | 6292 | |||
| align=left | align=left |  | 10.93 | 6.74 | 11.23 | 1.92 | 50.93 | 16.13 | 33.48 | 4.00 | DNS | DNS | DNF | ||||
| align=left | align=left |  | 11.49 | 6.29 | 12.40 | 1.83 | 52.30 | 16.59 | 37.06 | 4.00 | DNS | DNS | DNF | ||||
| align=left | align=left | 11.53 | 7.06 | 11.28 | 1.74 | 53.29 | DNS | DNS | DNS | DNS | DNS | DNF | |||||
| align=left | align=left | | 11.59 | 6.81 | 10.92 | 1.89 | DNS | DNS | DNS | DNS | DNS | DNS | DNF | ||||
| align=left | align=left |  | 11.99 | NM | DNS | DNS | DNS | DNS | DNS | DNS | DNS | DNS | DNF |
According to an unofficial count, 22 athletes from 17 countries participated in the event.