The men's decathlon event at the 2008 World Junior Championships in Athletics was held in Bydgoszcz, Poland, at Zawisza Stadium on 9 and 10 July. Junior implements were used, i.e. 99.0 cm (3'3) hurdles, 6 kg shot and 1.75 kg discus.
| Gold | Jan Felix Knobel | |
| Silver | Eduard Mikhan | |
| Bronze | Mihail Dudaš |
9/10 July
| Rank | Name | Nationality | 100m | LJ | SP | HJ | 400m | 110m H | DT | PV | JT | 1500m | Points | Notes | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| align=left | align=left | 11.47 (w: -0.3 m/s) | 7.12 | 16.17 | 1.96 | 50.52 | 14.81 (w: -0.1 m/s) | 43.96 | 4.60 | 66.27 | 4:47.44 | 7896 | |||||
| align=left | align=left | | 10.82 (w: -0.1 m/s) | 7.19 | 14.67 | 1.93 | 48.48 | 14.54 (w: -0.1 m/s) | 44.43 | 4.40 | 51.28 | 4:30.93 | 7894 | ||||
| align=left | align=left | | 11.03 (w: -0.1 m/s) | 7.17 | 14.50 | 1.93 | 48.66 | 14.83 (w: -0.1 m/s) | 43.31 | 4.30 | 51.31 | 4:42.11 | 7663 | ||||
| 4 | align=left | align=left | 11.19 (w: -0.1 m/s) | 6.74 | 15.69 | 1.90 | 50.50 | 15.30 (w: 0.9 m/s) | 45.01 | 4.20 | 58.41 | 4:40.49 | 7555 | ||||
| 5 | align=left | align=left |  | 11.32 (w: -0.1 m/s) | 6.31 | 16.02 | 1.90 | 51.54 | 15.74 (w: -0.9 m/s) | 45.38 | 4.60 | 63.45 | 4:40.35 | 7552 | |||
| 6 | align=left | align=left |  | 11.05 (w: -0.1 m/s) | 7.22 | 13.93 | 1.81 | 50.04 | 14.67 (w: -0.1 m/s) | 48.34 | 3.70 | 53.60 | 4:44.66 | 7443 | |||
| 7 | align=left | align=left |  | 11.25 (w: -0.3 m/s) | 6.87 | 13.63 | 1.99 | 49.45 | 15.02 (w: 0.9 m/s) | 39.96 | 3.80 | 53.14 | 4:40.52 | 7314 | |||
| 8 | align=left | align=left |  | 11.48 (w: 0.0 m/s) | 6.81 | 14.18 | 1.84 | 49.61 | 15.38 (w: -0.9 m/s) | 41.59 | 4.10 | 50.44 | 4:29.14 | 7250 | |||
| 9 | align=left | align=left | | 11.69 (w: 0.0 m/s) | 6.41 | 14.12 | 1.96 | 51.25 | 15.40 (w: -0.9 m/s) | 46.96 | 4.20 | 53.56 | 4:42.94 | 7236 | |||
| 10 | align=left | align=left |  | 11.25 (w: -0.3 m/s) | 6.62 | 12.04 | 1.81 | 49.33 | 14.23 (w: -0.1 m/s) | 42.64 | 4.20 | 46.83 | 4:40.37 | 7178 | |||
| 11 | align=left | align=left | | 11.37 (w: 0.0 m/s) | 6.50 | 12.31 | 1.96 | 51.13 | 16.83 (w: 0.9 m/s) | 48.09 | 3.90 | 64.71 | 4:41.65 | 7174 | |||
| 12 | align=left | align=left | 11.00 (w: 0.0 m/s) | 6.80 | 14.29 | 1.87 | 50.09 | 15.65 (w: -0.9 m/s) | 40.95 | 4.20 | 45.59 | 4:53.26 | 7124 | ||||
| 13 | align=left | Artur Liiv | align=left |  | 11.48 (w: 0.0 m/s) | 7.03 | 11.22 | 1.96 | 50.62 | 15.35 (w: -0.9 m/s) | 42.74 | 4.20 | 51.52 | 4:57.55 | 7076 | ||
| 14 | align=left | align=left |  | 11.39 (w: -0.1 m/s) | 7.38 | 13.93 | 1.96 | 53.00 | 16.19 (w: 0.9 m/s) | 40.41 | 4.40 | 48.15 | 5:06.01 | 7056 | |||
| 15 | align=left | align=left | | 11.91 (w: -0.3 m/s) | 6.43 | 13.51 | 1.93 | 51.99 | 15.24 (w: 0.9 m/s) | 33.75 | 4.60 | 49.70 | 4:42.87 | 6910 | |||
| 16 | align=left | align=left | | 11.58 (w: -0.3 m/s) | 6.44 | 12.92 | 1.78 | 51.87 | 15.03 (w: -0.1 m/s) | 41.80 | 4.40 | 46.56 | 5:05.80 | 6765 | |||
| 17 | align=left | align=left |  | 11.60 (w: -0.3 m/s) | 6.36 | 13.23 | 1.99 | 51.67 | 15.63 (w: -0.1 m/s) | 31.85 | 3.60 | 60.76 | 5:01.38 | 6698 | |||
| align=left | align=left |  | 10.79 (w: -0.1 m/s) | 6.71 | 13.28 | 1.87 | 48.18 | 15.41 (w: 0.9 m/s) | 32.95 | DNS | DNS | DNS | DNF | ||||
| align=left | align=left | | 11.81 (w: 0.0 m/s) | 6.86 | 14.40 | 1.93 | 53.76 | 15.96 (w: -0.9 m/s) | 39.76 | DNF | DNS | DNS | DNF |
According to an unofficial count, 19 athletes from 13 countries participated in the event.