The men's javelin throw event at the 2008 World Junior Championships in Athletics was held in Bydgoszcz, Poland, at Zawisza Stadium on 9 and 11 July.
| Gold | Robert Szpak | |
| Silver | Ihab El-Sayed | |
| Bronze | Ansis Brūns |
11 July
| Rank | Name | Nationality | Attempts | Result | Notes | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | ||||||||
| align=left | align=left | | 71.47 | 73.67 | 78.01 | 76.67 | 75.47 | 71.02 | 78.01 | ||||
| align=left | align=left | | 76.20 | 69.88 | 70.10 | 75.72 | x | 73.40 | 76.20 | ||||
| align=left | align=left | 59.97 | 72.23 | 70.15 | x | x | 75.31 | 75.31 | |||||
| 4 | align=left | align=left |  | 67.43 | 69.37 | 70.25 | 68.10 | 71.80 | 74.47 | 74.47 | |||
| 5 | align=left | align=left |  | 68.99 | 71.71 | x | 72.81 | 72.00 | 74.44 | 74.44 | |||
| 6 | align=left | align=left |  | 63.50 | x | 68.98 | 67.07 | 71.66 | 70.29 | 71.66 | |||
| 7 | align=left | align=left |  | 62.05 | 66.49 | 69.59 | 66.70 | 64.98 | 65.79 | 69.59 | |||
| 8 | align=left | align=left | | 69.07 | x | x | 65.82 | x | 68.38 | 69.07 | |||
| 9 | align=left | align=left |  | 68.88 | 68.35 | 68.09 | 68.88 | ||||||
| 10 | align=left | align=left |  | 66.97 | 65.02 | 68.79 | 68.79 | ||||||
| 11 | align=left | align=left | 67.49 | 67.16 | 65.45 | 67.49 | |||||||
| 12 | align=left | align=left |  | 65.21 | x | 62.19 | 65.21 | ||||||
9 July
| Rank | Name | Nationality | Attempts | Result | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | ||||||||
| 1 | align=left | align=left | | 67.94 | 71.06 | 69.31 | 71.06 | q | ||
| 2 | align=left | align=left | 67.06 | 70.61 | 66.05 | 70.61 | q | |||
| 3 | align=left | align=left | | 69.29 | 66.17 | x | 69.29 | q | ||
| 4 | align=left | align=left | | 69.27 | x | 66.16 | 69.27 | q | ||
| 5 | align=left | align=left | | 68.03 | 68.92 | 67.12 | 68.92 | q | ||
| 6 | align=left | align=left | 65.32 | 67.51 | 66.66 | 67.51 | ||||
| 7 | align=left | align=left |  | x | 65.63 | 64.46 | 65.63 | |||
| 8 | align=left | align=left |  | 60.44 | 62.35 | 60.48 | 62.35 | |||
| 9 | align=left | align=left |  | 60.28 | 61.73 | x | 61.73 | |||
| 10 | align=left | align=left | | 60.22 | 60.18 | 61.53 | 61.53 | |||
| 11 | align=left | align=left | | 60.13 | 59.80 | 59.67 | 60.13 | |||
| 12 | align=left | align=left | 57.79 | x | 55.32 | 57.79 | ||||
| align=left | align=left |  | x | x | x | NM | ||||
| Rank | Name | Nationality | Attempts | Result | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | ||||||||
| 1 | align=left | align=left | | 72.29 | - | - | 72.29 | Q | ||
| 2 | align=left | align=left | | 71.05 | x | 65.52 | 71.05 | q | ||
| 3 | align=left | align=left | 65.16 | x | 68.93 | 68.93 | q | |||
| 4 | align=left | align=left | | 67.65 | 63.83 | 68.92 | 68.92 | q | ||
| 5 | align=left | align=left | | 64.37 | 68.40 | 65.54 | 68.40 | q | ||
| 6 | align=left | align=left | | 65.19 | 67.79 | - | 67.79 | q | ||
| 7 | align=left | align=left | | 67.69 | 66.69 | 65.74 | 67.69 | q | ||
| 8 | align=left | align=left |  | 65.20 | 67.59 | 63.14 | 67.59 | |||
| 9 | align=left | align=left | x | 67.42 | 66.96 | 67.42 | ||||
| 10 | align=left | align=left |  | 64.58 | 63.94 | 60.78 | 64.58 | |||
| 11 | align=left | align=left | 62.36 | 62.38 | 62.44 | 62.44 | ||||
| 12 | align=left | align=left |  | 58.69 | 60.83 | x | 60.83 | |||
| 13 | align=left | align=left | | 60.66 | x | x | 60.66 | |||
According to an unofficial count, 26 athletes from 20 countries participated in the event.