The men's 20 kilometres road run event at the 1988 World Junior Championships in Athletics was held in Sudbury, Ontario, Canada, on 31 July.
| Gold | Metaferia Zeleke | |
| Silver | Thomas Osano | |
| Bronze | Abel Gisemba |
31 July
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| align=left | align=left | | 59:27 | ||||
| align=left | align=left | | 1:00:14 | ||||
| align=left | align=left | | 1:00:36 | ||||
| 4 | align=left | align=left |  | 1:00:54 | |||
| 5 | align=left | align=left | | 1:00:54 | |||
| 6 | align=left | align=left | 1:02:03 | ||||
| 7 | align=left | align=left | 1:02:33 | ||||
| 8 | align=left | align=left |  | 1:02:55 | |||
| 9 | align=left | align=left | | 1:03:06 | |||
| 10 | align=left | align=left | 1:03:42 | ||||
| 11 | align=left | align=left |  | 1:03:45 | |||
| 12 | align=left | align=left | | 1:03:57 | |||
| 13 | align=left | align=left |  | 1:04:00 | |||
| 14 | align=left | align=left | 1:04:26 | ||||
| 15 | align=left | align=left | 1:04:32 | ||||
| 16 | align=left | align=left |  | 1:04:54 | |||
| 17 | align=left | align=left |  | 1:05:03 | |||
| 18 | align=left | align=left | 1:05:34 | ||||
| 19 | align=left | align=left | | 1:05:52 | |||
| 20 | align=left | align=left |  | 1:06:06 | |||
| 21 | align=left | align=left | 1:06:28 | ||||
| 22 | align=left | align=left |  | 1:06:41 | |||
| 23 | align=left | align=left | 1:07:03 | ||||
| 24 | align=left | align=left | | 1:07:04 | |||
| 25 | align=left | align=left |  | 1:07:27 | |||
| 26 | align=left | align=left |  | 1:07:49 | |||
| 27 | align=left | align=left | | 1:08:08 | |||
| 28 | align=left | align=left | | 1:09:38 | |||
| 29 | align=left | align=left |  | 1:11:34 | |||
| 30 | align=left | align=left | 1:11:35 | ||||
| 31 | align=left | align=left | 1:12:02 | ||||
| 32 | align=left | align=left | 1:17:05 | ||||
| align=left | align=left |  | DNF | ||||
| align=left | align=left |  | DNF |
According to an unofficial count, 34 athletes from 25 countries participated in the event.