This study is a randomized outcome trial of a social network HIV prevention intervention for at-risk labor migrants who have arrived in St. Petersburg, Russia, to seek work. Most come to St. Petersburg from Moldova, Tajikistan, Uzbekistan, Ukraine, and other poor post-Soviet republics. While living in Russia, labor migrants are also living in a city and country with high HIV prevalence. Many labor migrants have limited awareness of AIDS, and most are living in a location far from their spouses, family members, and others. For that reason, labor migrants are vulnerable to risk behavior for contracting HIV.