This report presents data on participation in online or offline prevention activities among a sample of New York City men who have sex with men (MSM) recruited online between April-August of 2007 who use the Internet to meet sex partners. The analysis focuses on the 1,124 men who reported sex with a main or casual partner in the past 12 months. Over half (53%) of the MSM reported unprotected anal intercourse (UAI) in the past year. Data from our multivariate analysis indicate that MSM who participate in online or offline prevention activities were less likely to engage in UAI.