The men's long jump event at the 1986 World Junior Championships in Athletics was held in Athens, Greece, at Olympic Stadium on 17 and 18 July.
| Gold | Dietmar Haaf | |
| Silver | Ivo Krsek | |
| Bronze | Thomas Wolf |
18 July
| Rank | Name | Nationality | Result | Notes | |||
|---|---|---|---|---|---|---|---|
| align=left | align=left | 7.93 | |||||
| align=left | align=left | 7.87 | |||||
| align=left | align=left | 7.77 | |||||
| 4 | align=left | align=left |  | 7.71 | |||
| 5 | align=left | align=left | 7.69 | ||||
| 6 | align=left | align=left |  | 7.64 | |||
| 7 | align=left | align=left |  | 7.59 | |||
| 8 | align=left | align=left | 7.58 | ||||
| 9 | align=left | align=left | 7.51 | ||||
| 10 | align=left | align=left | 7.49 | ||||
| 11 | align=left | align=left |  | 7.46 w | |||
| 12 | align=left | align=left |  | 7.42 |
17 Jul
| Rank | Name | Nationality | Result | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 7.73 | Q | |||
| 2 | align=left | align=left | 7.71 | Q | |||
| 3 | align=left | align=left | 7.47 | q | |||
| 4 | align=left | align=left | | 7.43 | q | ||
| 5 | align=left | align=left | | 7.34 | |||
| 6 | align=left | align=left | 7.21 | ||||
| align=left | align=left | 7.21 | |||||
| 8 | align=left | align=left |  | 7.19 | |||
| 9 | align=left | align=left |  | 7.13 | |||
| align=left | align=left | 7.13 | |||||
| 11 | align=left | align=left |  | 7.08 | |||
| 12 | align=left | align=left |  | 7.00 | |||
| 13 | align=left | align=left | 6.99 | ||||
| 14 | align=left | align=left | 6.81 | ||||
| 15 | align=left | align=left |  | 6.78 | |||
| 16 | align=left | align=left |  | 6.47 | |||
| 17 | align=left | align=left |  | 6.45 | |||
| 18 | align=left | align=left | 6.22 | ||||
| 19 | align=left | align=left | 5.91 | ||||
| 20 | align=left | align=left |  | 5.87 | |||
| align=left | align=left | NM | |||||
| align=left | align=left |  | NM | ||||
| align=left | align=left | NM |
| Rank | Name | Nationality | Result | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 7.91 | Q | |||
| 2 | align=left | align=left | 7.75 | Q | |||
| 3 | align=left | align=left | | 7.67 | Q | ||
| 4 | align=left | align=left | 7.63 | Q | |||
| 5 | align=left | align=left | 7.62 | Q | |||
| 6 | align=left | align=left | | 7.60 | Q | ||
| 7 | align=left | align=left | | 7.45 | q | ||
| 8 | align=left | align=left | | 7.43 | q | ||
| 9 | align=left | align=left | | 7.41 | |||
| 10 | align=left | align=left | 7.33 | ||||
| 11 | align=left | align=left |  | 7.30 | |||
| 12 | align=left | align=left |  | 7.25 | |||
| 13 | align=left | align=left |  | 7.24 | |||
| 14 | align=left | align=left | 7.20 | ||||
| align=left | align=left |  | 7.20 | ||||
| 16 | align=left | align=left |  | 7.06 | |||
| 17 | align=left | align=left | 6.95 | ||||
| 18 | align=left | align=left | | 6.89 | |||
| 19 | align=left | align=left | 6.32 | ||||
| 20 | align=left | align=left | | 6.00 | |||
| 21 | align=left | align=left |  | 5.67 |
According to an unofficial count, 44 athletes from 36 countries participated in the event.