This study examines awareness of and experiences with post-exposure prophylaxis (PEP) and pre-exposure prophylaxis (PrEP) among 228 men recruited in Boston, Pittsburgh, and San Juan between 12/2010 and 6/2012. All of them reported having condomless anal sex with a man in the prior year. Overall, 41% had heard of PEP, ranging from 16% in San Juan to 64% in Boston. Only 21% had heard of PrEP, ranging from 8% in San Juan to 36% in Boston. Three had used PEP, and none had used PrEP. After the methods were described to participants, interest in both was high, with intentions to use PEP and PrEP respectively at 9.1 and 7.7 (10-point scale). Increased public education is needed to raise awareness of these HIV prevention methods, especially among MSM who acknowledge potential risk behavior. It also seems likely that many such men would use these methods once they become aware of them.