The men's decathlon event at the 1998 World Junior Championships in Athletics was held in Annecy, France, at Parc des Sports on 29 and 30 July. Senior implements (106.7 cm (3'6) hurdles, 7257g shot, 2 kg discus) were used.
| Gold | Aki Heikkinen | |
| Silver | Thomas Pöge | |
| Bronze | Jaakko Ojaniemi |
29/30 July
| Rank | Name | Nationality | 100m | LJ | SP | HJ | 400m | 110m H | DT | PV | JT | 1500m | Points | Notes | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| align=left | align=left | | 11.43 (w: -0.5 m/s) | 6.80 | 12.83 | 1.89 | 50.70 | 15.31 (w: -1.2 m/s) | 38.72 | 4.60 | 65.77 | 4:32.01 | 7476 | ||||
| align=left | align=left | 11.43 (w: -0.3 m/s) | 6.93 | 13.12 | 1.98 | 51.51 | 14.98 (w: -0.1 m/s) | 35.03 | 4.60 | 57.92 | 4:45.09 | 7332 | |||||
| align=left | align=left | | 11.11 (w: -1.3 m/s) | 7.25 | 12.86 | 1.95 | 50.56 | 15.59 (w: -1.2 m/s) | 36.42 | 4.20 | 54.62 | 4:48.38 | 7246 | ||||
| 4 | align=left | align=left | 11.23 (w: -0.5 m/s) | 7.13 | 10.78 | 1.86 | 49.53 | 14.55 (w: -1.2 m/s) | 33.57 | 4.60 | 46.07 | 4:33.38 | 7187 | ||||
| 5 | align=left | align=left | 10.84 (w: -0.5 m/s) | 7.40 | 11.90 | 1.80 | 48.59 | 15.14 (w: -0.1 m/s) | 34.95 | 4.00 | 48.66 | 4:54.42 | 7089 | ||||
| 6 | align=left | align=left |  | 11.24 (w: -1.3 m/s) | 7.14 | 10.89 | 1.98 | 48.28 | 14.92 (w: -1.2 m/s) | 33.72 | 4.20 | 41.76 | 4:41.85 | 7082 | |||
| 7 | align=left | align=left |  | 11.48 (w: -0.3 m/s) | 7.04 | 12.83 | 1.89 | 51.46 | 15.80 (w: -1.2 m/s) | 37.86 | 4.30 | 52.64 | 4:43.75 | 7054 | |||
| 8 | align=left | align=left |  | 11.75 (w: -0.3 m/s) | 6.76 | 11.69 | 1.89 | 50.07 | 15.49 (w: -0.6 m/s) | 37.24 | 4.50 | 44.86 | 4:21.68 | 7035 | |||
| 9 | align=left | align=left |  | 11.50 (w: -0.3 m/s) | 6.94 | 11.92 | 1.83 | 52.57 | 16.63 (w: -1.2 m/s) | 38.37 | 4.90 | 53.98 | 4:45.75 | 6975 | |||
| 10 | align=left | align=left |  | 11.48 (w: -1.3 m/s) | 6.68 | 11.90 | 2.01 | 51.36 | 15.43 (w: -0.1 m/s) | 38.11 | 4.10 | 57.63 | 5:05.16 | 6963 | |||
| 11 | align=left | align=left | 11.31 (w: -0.5 m/s) | 7.03 | 12.63 | 1.86 | 50.07 | 15.07 (w: -0.6 m/s) | 36.20 | 4.10 | 48.24 | 5:06.39 | 6909 | ||||
| 12 | align=left | align=left |  | 11.19 (w: -1.3 m/s) | 6.79 | 11.64 | 1.65 | 49.55 | 15.48 (w: -0.6 m/s) | 40.55 | 3.50 | 62.15 | 4:45.67 | 6872 | |||
| 13 | align=left | align=left |  | 11.15 (w: -0.5 m/s) | 6.23 | 13.64 | 2.01 | 50.53 | 15.77 (w: -0.6 m/s) | 41.52 | 3.40 | 48.14 | 5:06.49 | 6769 | |||
| 14 | align=left | align=left |  | 11.60 (w: -0.5 m/s) | 6.47 | 10.59 | 1.95 | 50.57 | 15.45 (w: -0.6 m/s) | 35.80 | 4.30 | 50.54 | 4:54.12 | 6760 | |||
| 15 | align=left | align=left | 11.19 (w: -0.5 m/s) | 6.33 | 12.56 | 1.80 | 51.87 | 15.41 (w: -0.1 m/s) | 38.98 | 4.20 | 44.45 | 4:57.82 | 6672 | ||||
| 16 | align=left | align=left |  | 11.51 (w: -0.3 m/s) | 6.87 | 11.87 | 1.95 | 53.38 | 16.15 (w: -0.1 m/s) | 33.25 | 3.80 | 52.18 | 5:29.02 | 6387 | |||
| 17 | align=left | align=left | | 11.51 (w: -1.3 m/s) | 6.37 | 11.58 | 1.80 | 52.05 | DQ | 36.16 | 4.90 | 41.15 | DNS | 5275 | |||
| align=left | align=left | | 11.70 (w: -1.3 m/s) | 6.82 | 12.54 | 1.89 | 51.37 | 15.63 (w: -0.1 m/s) | 36.28 | 4.30 | DNS | DNS | DNF | ||||
| align=left | align=left |  | 11.33 (w: -0.5 m/s) | 6.78 | 10.00 | 1.95 | 50.82 | 17.38 (w: -1.2 m/s) | 29.45 | DNF | 46.62 | DNS | DNF | ||||
| align=left | align=left |  | 11.54 (w: -0.3 m/s) | 6.44 | 12.13 | 1.89 | 52.27 | 15.17 (w: -0.6 m/s) | 36.66 | DNF | DNS | DNS | DNF | ||||
| align=left | align=left |  | 11.38 (w: -0.3 m/s) | 6.97 | 13.78 | 1.83 | 50.96 | 17.01 (w: -1.2 m/s) | DNS | DNS | DNS | DNS | DNF | ||||
| align=left | align=left | | 10.94 (w: -1.3 m/s) | 6.63 | 11.64 | 1.77 | 48.22 | 20.08 (w: -0.6 m/s) | DNS | DNS | DNS | DNS | DNF |
According to an unofficial count, 22 athletes from 17 countries participated in the event.