In two decades since HIV was first diagnosed, AIDS has claimed 20 million lives and currently 40 million people are infected with HIV/AIDS. HIV/AIDS is inextricably linked to poverty and erodes hard-won livelihoods of the world poorest communities. The research study conducted under this thesis investigates HIV Risk Behavior Practice and helps to fight HIV/AIDS by changing people behavior. The sample involved in the study consists of 200 individuals living in Addis Ababa: Ethiopia. The behavior that has been taken into consideration is HIV Risk Behavior and it includes: number of sexual partners, sexual practice with casual and high risk partners, condom use, sexual trading, using alcohol and drug for sexual initiation, and deviant sexual practice like anal sex. The data has been collected by questionnaire. The findings of the study suggested that a significant portion of the research participants had multiple sexual partners, sexual practices with casual and high-risk partners, sex without condom, involved in anal sex, used alcohol and drug for sexual initiation and engaged in sexual trading which are some of the major factors that contribute to the wide spread of HIV.