Heats

First 4 of each Heat (Q) and the next 4 fastest (q) qualified for the quarterfinals.

Rank	Heat	Name	Nationality	Time	Notes
1	6	Jerome Young	United States	45.34	Q
2	3	Sanderlei Claro Parrela	Brazil	45.35	Q
3	3	Tyree Washington	United States	45.35	Q
4	6	Mark Richardson	Great Britain	45.44	Q
5	3	Sugath Tillakeratne	Sri Lanka	45.58	Q, NR
6	3	Ibrahima Wade	Senegal	45.61	Q
7	4	Iwan Thomas	Great Britain	45.62	Q
8	5	Michael Johnson	United States	45.66	Q
9	3	Matthias Rusterholz	Switzerland	45.76	q, SB
10	4	Davian Clarke	Jamaica	45.77	Q
11	5	Eswort Coombs	Saint Vincent and the Grenadines	45.78	Q
12	6	Sunday Bada	Nigeria	45.79	Q
13	4	Tomasz Czubak	Poland	45.82	Q
14	5	Hachim Ndiaye	Senegal	45.84	Q
14	7	Štefan Balošák	Slovakia	45.84	Q
16	1	Jamie Baulch	Great Britain	45.85	Q
16	3	Jean-Louis Rapnouil	France	45.85	q
18	5	Kennedy Ochieng	Kenya	45.88	Q
18	6	Ibrahim Ismail Muftah	Qatar	45.88	Q
20	2	Michael McDonald	Jamaica	45.89	Q
21	5	Marco Vaccari	Italy	46.00	q
22	1	Roxbert Martin	Jamaica	46.04	Q
23	4	Arnaud Malherbe	South Africa	46.08	Q
24	1	Tawanda Chiwira	Zimbabwe	46.09	Q
25	7	Clement Chukwu	Nigeria	46.10	Q
26	7	Robert Maćkowiak	Poland	46.15	Q
27	2	Davis Kamoga	Uganda	46.17	Q
28	4	Samir-Adel Louahla	Algeria	46.22	q
29	2	Alejandro Cardenas	Mexico	46.26	Q
30	5	Odair da Costa	São Tomé and Príncipe	46.48	PB
31	6	Soloveni Nakaunicina	Fiji	46.51
32	5	Jan Poděbradský	Czech Republic	46.52
33	1	Benjamin Youla	Republic of the Congo	46.62	Q, NR
34	4	Konstantinos Moumoulidis	Greece	46.64
35	1	Roman Galkin	Ukraine	46.82
36	1	Antonio Andrés	Spain	46.94
37	7	Rafik Elouardi	Austria	46.95
38	6	Shigekazu Omori	Japan	47.09
39	3	Kenmore Hughes	Antigua and Barbuda	47.11	SB
40	2	Shon Ju-Il	South Korea	47.47	Q
41	4	Evripides Demosthenous	Cyprus	47.57
42	2	Liod Kgopong	South Africa	47.66
43	2	Kendon Maynard	United States Virgin Islands	47.83
44	7	Dennis Darling	Bahamas	47.96
45	6	Eugene Farrell	Ireland	48.20	SB
46	7	Angelo Ignatius	Netherlands Antilles	49.01
47	2	Mohsin Munir	Pakistan	49.61
48	6	Bashir Mohamed Al Khewani	Yemen	50.96
	7	Antonio Pettigrew	United States	DQ	Q
	1	Neil de Silva	Trinidad and Tobago	DNF
	2	Jude Monye	Nigeria	DNS

Quarterfinals

First 3 of each Heat (Q) and the next 4 fastest (q) qualified for the semifinals.

Rank	Heat	Name	Nationality	Time	Notes
1	4	Jerome Young	United States	44.87	Q
2	1	Iwan Thomas	Great Britain	44.98	Q
3	4	Mark Richardson	Great Britain	45.05	Q
4	2	Jamie Baulch	Great Britain	45.06	Q
4	3	Clement Chukwu	Nigeria	45.06	Q
6	3	Tyree Washington	United States	45.09	Q
7	4	Michael McDonald	Jamaica	45.16	Q
8	2	Davis Kamoga	Uganda	45.25	Q
9	1	Robert Maćkowiak	Poland	45.26	Q, NR
10	3	Davian Clarke	Jamaica	45.27	Q
11	1	Roxbert Martin	Jamaica	45.37	q
11	4	Sunday Bada	Nigeria	45.37	q, SB
13	2	Ibrahima Wade	Senegal	45.38	Q
14	2	Michael Johnson	United States	45.39	q
15	4	Tomasz Czubak	Poland	45.41	q, PB
16	3	Hachim Ndiaye	Senegal	45.44	PB
17	2	Eswort Coombs	Saint Vincent and the Grenadines	45.47
18	1	Štefan Balošák	Slovakia	45.48
19	1	Matthias Rusterholz	Switzerland	45.89
20	3	Sugath Tillakeratne	Sri Lanka	46.11
21	4	Ibrahim Ismail Muftah	Qatar	46.12
22	2	Jean-Louis Rapnouil	France	46.14
23	2	Tawanda Chiwira	Zimbabwe	46.22
24	4	Samir-Adel Louahla	Algeria	46.23
25	3	Kennedy Ochieng	Kenya	46.28
26	2	Benjamin Youla	Republic of the Congo	46.29	NR
27	3	Marco Vaccari	Italy	46.32
28	1	Alejandro Cardenas	Mexico	46.63
29	4	Arnaud Malherbe	South Africa	46.73
30	1	Shon Ju-Il	South Korea	47.36
	1	Antonio Pettigrew	United States	DQ	Q
	3	Sanderlei Claro Parrela	Brazil	DNS

Semifinals

First 4 of each Semifinal qualified directly (Q) for the final.

Rank	Heat	Name	Nationality	Time	Notes
1	2	Michael Johnson	United States	44.37	Q
2	2	Jerome Young	United States	44.50	Q, SB
3	2	Davis Kamoga	Uganda	44.57	Q, SB
4	1	Tyree Washington	United States	44.61	Q
4	2	Iwan Thomas	Great Britain	44.61	Q
6	1	Mark Richardson	Great Britain	44.62	Q, SB
7	1	Jamie Baulch	Great Britain	44.69	Q, SB
8	1	Davian Clarke	Jamaica	45.07
9	2	Clement Chukwu	Nigeria	45.26
10	1	Ibrahima Wade	Senegal	45.47
11	2	Roxbert Martin	Jamaica	45.49
12	2	Tomasz Czubak	Poland	45.51
13	2	Michael McDonald	Jamaica	45.74
14	1	Sunday Bada	Nigeria	45.96
	1	Antonio Pettigrew	United States	DQ	Q
	1	Robert Maćkowiak	Poland	DNS

Final

Rank	Lane	Name	Nationality	Time	Notes
	4	Michael Johnson	United States	44.12
	7	Davis Kamoga	Uganda	44.37	NR
	3	Tyree Washington	United States	44.39	PB
4	5	Mark Richardson	Great Britain	44.47	PB
5	6	Jerome Young	United States	44.51
6	2	Iwan Thomas	Great Britain	44.52
7	1	Jamie Baulch	Great Britain	45.22
	8	Antonio Pettigrew	United States	DQ