The epidemiological trend of increasing HIV incidence rates due to sexual transmission in Central and Eastern Europe has been documented. The current review analyzed research articles that report on a wide spectrum of vulnerable populations from this world region. Studies of injection drug users, commercial sex workers, men who have sex with men, adolescents and young adults all reported inconsistent condom use. However, these patterns varied across populations and geographic areas. Populations in former Soviet countries—most affected by HIV—also often appeared to have lower condom use rates. Intensified, comprehensive, and locally-tailored measures to curb sexual HIV transmission are urgently needed. Social development programs need to incorporate HIV prevention.