Athletics at the 2010 South American Games – Men's 400 metres

The Men's 400m event at the 2010 South American Games was held on March 20, with the heats at 11:30 and the Final at 18:45.

Results
Results were published.

Heat 2
†: Not eligible for the South American Under-23 Championships.

Final
†: Not eligible for the South American Under-23 Championships.