The two main contenders for the event were the reigning World Champions, the United States, and the reigning Olympic Champions, Jamaica.
Jamaica held the world record at 37.10 (which was later rescinded), which was established at the 2008 Summer Olympics in Beijing, while the United States entered with the 2009 overall season-best 37.85.
* Runners who participated in the heats only and received medals.
No new world or championship record was set during this competition.
Key: DNF = Did not finish, DNS = Did not start, DQ = Disqualified, Q = qualification by place in heat, q = qualification by overall place, SB = Seasonal best Key: CR = Championship record, NR = National record, SB = Seasonal best