# 1990 World Junior Championships in Athletics – Men's 400 metres

The men's 400 metres event at the 1990 World Junior Championships in Athletics was held in Plovdiv, Bulgaria, at Deveti Septemvri Stadium on 8, 9 and 10 August.

## Medalists

| Gold | Chris Nelloms United States |
| Silver | Rico Lieder East Germany |
| Bronze | Mark Richardson United Kingdom |

## Results
### Final

10 August
| Rank | Name | Nationality | Time |
| | Chris Nelloms | United States | 45.43 |
| | Rico Lieder | East Germany | 46.28 |
| | Mark Richardson | United Kingdom | 46.33 |
| 4 | Dmitriy Golovastov | Soviet Union | 46.43 |
| 5 | Derek Mills | United States | 46.44 |
| 6 | Ibrahim Ismail | Qatar | 46.52 |
| 7 | Du'aine Thorne-Ladejo | United Kingdom | 47.53 |
| | Amar Hecini | Algeria | DNF |

### Semifinals

9 August

#### Semifinal 1

| Rank | Name | Nationality | Time | Notes |
| 1 | Chris Nelloms | United States | 45.93 | Q |
| 2 | Mark Richardson | United Kingdom | 46.34 | Q |
| 3 | Rico Lieder | East Germany | 46.43 | Q |
| 4 | Dmitriy Golovastov | Soviet Union | 46.47 | Q |
| 5 | Joseph Chepsiror Kiptanui | Kenya | 46.48 | |
| 6 | Mathias Rusterholz | Switzerland | 47.04 | |
| 7 | Inaldo de Sena | Brazil | 47.09 | |
| 8 | Daniel England | Jamaica | 47.70 | |

#### Semifinal 2

| Rank | Name | Nationality | Time | Notes |
| 1 | Ibrahim Ismail | Qatar | 46.06 | Q |
| 2 | Amar Hecini | Algeria | 46.08 | Q |
| 3 | Derek Mills | United States | 46.43 | Q |
| 4 | Du'aine Thorne-Ladejo | United Kingdom | 46.66 | Q |
| 5 | Paul Greene | Australia | 46.71 | |
| 6 | Kennedy Ochieng | Kenya | 46.88 | |
| 7 | Florian Hennig | East Germany | 47.00 | |
| 8 | Ronald Thorne | Barbados | 48.11 | |

### Heats

8 August

#### Heat 1

| Rank | Name | Nationality | Time | Notes |
| 1 | Chris Nelloms | United States | 46.83 | Q |
| 2 | Amar Hecini | Algeria | 46.86 | Q |
| 3 | Matthew Burmeister | Australia | 47.98 | |
| 4 | Yusuke Horikoshi | Japan | 48.06 | |
| 5 | Štefan Balošák | Czechoslovakia | 48.57 | |
| 6 | Alain Sierro | Switzerland | 49.24 | |
| 7 | Carl Casey | Antigua and Barbuda | 49.40 | |
| 8 | Foday Sillah | Sierra Leone | 50.33 | |

#### Heat 2

| Rank | Name | Nationality | Time | Notes |
| 1 | Kennedy Ochieng | Kenya | 46.98 | Q |
| 2 | Ibrahim Ismail | Qatar | 47.03 | Q |
| 3 | Daniel England | Jamaica | 47.60 | q |
| 4 | Terry Harewood | Barbados | 48.39 | |
| 5 | Michael Börner | West Germany | 48.46 | |
| 6 | Julio Caballero | Paraguay | 48.68 | |

#### Heat 3

| Rank | Name | Nationality | Time | Notes |
| 1 | Dmitriy Golovastov | Soviet Union | 46.89 | Q |
| 2 | Paul Greene | Australia | 46.96 | Q |
| 3 | Florian Hennig | East Germany | 47.43 | q |
| 4 | Ronald Thorne | Barbados | 47.47 | q |
| 5 | Gary Reid | Canada | 47.94 | |
| 6 | José Mendes | Portugal | 47.99 | |
| 7 | Perry Dinan | New Zealand | 49.04 | |

#### Heat 4

| Rank | Name | Nationality | Time | Notes |
| 1 | Rico Lieder | East Germany | 47.00 | Q |
| 2 | Du'aine Thorne-Ladejo | United Kingdom | 47.03 | Q |
| 2 | Joseph Chepsiror Kiptanui | Kenya | 47.03 | Q |
| 4 | Nilton Messias | Brazil | 47.73 | |
| 5 | Aleksandr Angelov | Soviet Union | 47.78 | |
| 6 | Masayoshi Kan | Japan | 48.49 | |

#### Heat 5

| Rank | Name | Nationality | Time | Notes |
| 1 | Mark Richardson | United Kingdom | 46.64 | Q |
| 2 | Derek Mills | United States | 46.68 | Q |
| 3 | Inaldo de Sena | Brazil | 47.36 | q |
| 4 | Mathias Rusterholz | Switzerland | 47.45 | q |
| 5 | Konstantin Babalievski | Bulgaria | 47.74 | |
| 6 | Matija Šestak | Yugoslavia | 49.05 | |
| 7 | Feye Girma | Ethiopia | 50.21 | |
| 8 | Nour Moustafa | North Yemen | 54.43 | |

## Participation

According to an unofficial count, 35 athletes from 25 countries participated in the event.
* Algeria (1)
* Antigua and Barbuda (1)
* Australia (2)
* Barbados (2)
* Brazil (2)
* Bulgaria (1)
* Canada (1)
* Czechoslovakia (1)
* East Germany (2)
* Ethiopia (1)
* Jamaica (1)
* Japan (2)
* Kenya (2)
* New Zealand (1)
* North Yemen (1)
* Paraguay (1)
* Portugal (1)
* Qatar (1)
* Sierra Leone (1)
* Soviet Union (2)
* Switzerland (2)
* United Kingdom (2)
* United States (2)
* West Germany (1)
* Yugoslavia (1)