The women's 100 metres hurdles event at the 1986 World Junior Championships in Athletics was held in Athens, Greece, at Olympic Stadium on 17 and 18 July.
| Gold | Heike Tillack | |
| Silver | Aliuska López | |
| Bronze | Tanya Davis |
18 July
Wind: -0.8 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| align=left | align=left | 13.10 | |||||
| align=left | align=left | | 13.14 | ||||
| align=left | align=left | | 13.46 | ||||
| 4 | align=left | align=left | 13.52 | ||||
| 5 | align=left | align=left |  | 13.62 | |||
| 6 | align=left | align=left |  | 13.96 | |||
| 7 | align=left | align=left | 14.03 | ||||
| 8 | align=left | align=left |  | 14.35 |
18 July
Wind: -0.3 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 13.52 | Q | |||
| 2 | align=left | align=left | | 13.52 | Q | ||
| 3 | align=left | align=left | | 13.80 | Q | ||
| 4 | align=left | align=left | | 14.10 | Q | ||
| 5 | align=left | align=left | 14.11 | ||||
| 6 | align=left | align=left | 14.16 | ||||
| 7 | align=left | align=left |  | 14.92 | |||
| align=left | align=left | | DNS |
Wind: +1.1 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.73 | Q | ||
| 2 | align=left | align=left | | 13.94 | Q | ||
| 3 | align=left | align=left | 14.01 | Q | |||
| 4 | align=left | align=left | 14.11 | Q | |||
| 5 | align=left | align=left | | 14.28 | |||
| 6 | align=left | align=left | | 14.42 | |||
| 7 | align=left | align=left |  | 14.47 | |||
| align=left | align=left | DNS |
17 July
Wind: +0.4 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.60 | Q | ||
| 2 | align=left | align=left | 13.68 | Q | |||
| 3 | align=left | align=left | | 14.12 | Q | ||
| 4 | align=left | align=left | | 14.26 | Q | ||
| 5 | align=left | align=left | 14.33 | ||||
| 6 | align=left | align=left | 14.51 | ||||
| 7 | align=left | align=left | 15.57 |
Wind: -1.9 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 13.61 | Q | |||
| 2 | align=left | align=left | 14.01 | Q | |||
| 3 | align=left | align=left | | 14.11 | Q | ||
| 4 | align=left | align=left | | 14.60 | Q | ||
| 5 | align=left | align=left |  | 14.95 | |||
| 6 | align=left | align=left |  | 15.15 | |||
| 7 | align=left | align=left | 16.11 |
Wind: +1.3 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.59 | Q | ||
| 2 | align=left | align=left | | 13.97 | Q | ||
| 3 | align=left | align=left | 14.15 | Q | |||
| 4 | align=left | align=left | 14.16 | Q | |||
| 5 | align=left | align=left | | 14.24 | |||
| 6 | align=left | align=left |  | 14.62 | |||
| 7 | align=left | align=left | 15.28 |
Wind: +0.3 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.62 | Q | ||
| 2 | align=left | align=left | 14.04 | Q | |||
| 3 | align=left | align=left | | 14.20 | Q | ||
| 4 | align=left | align=left | | 14.38 | Q | ||
| 5 | align=left | align=left | | 14.66 | |||
| 6 | align=left | align=left | 14.72 | ||||
| 7 | align=left | align=left | 15.29 | ||||
| 8 | align=left | align=left |  | 15.95 |
According to an unofficial count, 29 athletes from 22 countries participated in the event.