Sexually transmitted infection was found in 16.5% of the men who have sex with men with a postexposure prophylaxis indication. Chlamydia and gonorrhea screening was repeated after 14 days. Among those who were initially sexually transmitted infection negative, 4.1% had chlamydia or gonorrhea. In postexposure prophylaxis-indicated men who have sex with men, repeat chlamydia and gonorrhea screening is advised to diagnose infections not apparent at baseline screening.