Athletics at the 2003 All-Africa Games – Men's 400 metres
The men's 400 metres at the 2003 All-Africa Games were held on October 11–13.
Medalists
Results
Heats
Qualification: First 4 of each heat and the next 4 fastest qualified for the semifinals.| Rank | Heat | Name | Nationality | Time | Notes |
| 1 | 4 | Lloyd Zvasiya | 45.70 | Q | |
| 2 | 4 | Nagmeldin Ali Abubakr | 45.89 | Q | |
| 3 | 2 | Vincent Mumo | 46.28 | Q | |
| 4 | 4 | California Molefe | 46.31 | Q | |
| 5 | 2 | Musa Audu | 46.37 | Q | |
| 6 | 1 | Johnson Kubisa | 46.54 | Q | |
| 7 | 5 | Ezra Sambu | 46.67 | Q | |
| 8 | 3 | Amin Badany Goma'a | 46.87 | Q | |
| 9 | 2 | Seydina Doucouré | 46.92 | Q | |
| 10 | 1 | Saul Weigopwa | 47.09 | Q | |
| 10 | 3 | Sofiane Labidi | 47.09 | Q | |
| 12 | 5 | Young Talkmore Nyongani | 47.15 | Q | |
| 13 | 3 | Jeffrey Wilson | 47.20 | Q | |
| 14 | 4 | James Godday | 47.31 | Q | |
| 15 | 2 | Fernando Augustin | 47.43 | Q | |
| 16 | 3 | Saliou Mbaye | 47.59 | Q | |
| 17 | 5 | Alemayehu Abebo | 47.82 | Q | |
| 18 | 1 | Hassan Fullah | 47.91 | Q | |
| 18 | 5 | Kapena Rukero | 47.91 | Q | |
| 20 | 4 | Narcisse Tévoédjre | 47.93 | q | |
| 21 | 5 | Albert Kobba | 48.09 | q | |
| 22 | 1 | Brian Veron | 48.43 | Q | |
| 23 | 3 | Oumar Bella Bah | 48.50 | q | |
| 24 | 4 | Amadou Bocoum | 48.80 | q | |
| 25 | 2 | Youba Hmeida | 48.92 | ||
| 26 | 3 | Samuel Kiazolu | 49.17 | ||
| 27 | 2 | Mohamed Abdel Wahid | 49.28 | ||
| 28 | 2 | Varney Saidi | 49.32 | ||
| 29 | 1 | Moses Kondowe | 49.71 | ||
| 30 | 4 | David Aruna | 50.12 | ||
| 31 | 5 | Ghirmay Tukabo | 50.54 | ||
| 32 | 1 | Kitenge Fibel | 50.56 | ||
| 33 | 4 | Edgar Mbakouo Tsambi | 51.48 | ||
| 1 | Fredrerick Kimou | ||||
| 5 | Arlindo Leocadio Pinheiro |
Semifinals
Qualification: First 2 of each semifinal and the next 2 fastest qualified for the final.| Rank | Heat | Name | Nationality | Time | Notes |
| 1 | 2 | Lloyd Zvasiya | 45.51 | Q | |
| 2 | 3 | Sofiane Labidi | 45.58 | Q | |
| 3 | 3 | Ezra Sambu | 45.65 | Q | |
| 4 | 1 | Nagmeldin Ali Abubakr | 45.93 | Q | |
| 5 | 1 | Vincent Mumo | 46.20 | Q | |
| 6 | 2 | California Molefe | 46.24 | Q | |
| 7 | 3 | Johnson Kubisa | 46.38 | q | |
| 8 | 1 | Musa Audu | 46.52 | q | |
| 9 | 2 | Saul Weigopwa | 46.70 | ||
| 10 | 3 | James Godday | 46.71 | ||
| 11 | 1 | Jeffrey Wilson | 47.00 | ||
| 12 | 2 | Amin Badany Goma'a | 47.15 | ||
| 13 | 2 | Saliou Mbaye | 47.20 | ||
| 14 | 2 | Fernando Augustin | 47.30 | ||
| 15 | 3 | Young Talkmore Nyongani | 47.45 | ||
| 16 | 3 | Narcisse Tévoédjre | 47.76 | ||
| 17 | 1 | Seydina Doucouré | 47.96 | ||
| 18 | 3 | Hassan Fullah | 48.30 | ||
| 19 | 1 | Alemayehu Abebo | 48.35 | ||
| 20 | 1 | Kapena Rukero | 48.62 | ||
| 21 | 2 | Albert Kobba | 48.85 | ||
| 22 | 1 | Amadou Bocoum | 48.97 | ||
| 23 | 3 | Oumar Bella Bah | 49.07 | ||
| 24 | 2 | Brian Veron | 49.29 |