Back Ground. Sexuality is experienced and expressed in thoughts, fantasies, desires, beliefs, attitudes, values, behaviors, practices, roles and relationships .The influences of families and peers on sexual risk behavior and risk perception of youths are not well addressed Objectives: To assess risk sexual behaviors among adults at Adigrat Town, Tigray, North Ethiopia. Methods: A community based cross sectional study from August 27-September, 15, 2014. A total of 327 adults who live in selected households were involved in the study. Data was collected using pre-tested self-administered questionnaires. Data was analyzed using SPSS version 20 statistical package, summarized and presented using tables, descriptive measures and statistical diagrams.P-value and odds ratio was used to interpret significant variables. Result: One hundred seventy five (53.5%) of respondents were in the age 15-26 years. Two Hundred ninety nine (91.4%) of the participants had sexual intercourse experiences. From the total respondents, only137 (41.9%) of the participants had sexual intercourse experiences at the first time between 17 and above years old. The majority of the 119(36.4%)of the participants had sexual intercourse behavior with 1 person during their life. However, 47(14.4%) had sexual intercourse with Multiple partners (6 or more people). Almost half of the participants 191(58.4%) were responded that they intends to continue relationship with first partner. Conclusion: The high risk practice and necessitates intervention and low knowledge on sexual risk behavior. Because of this respondent must know about importance of identify risk sexual behaviors and prevalence of sexual behaviors. Future research should evaluate interventions targeted to adults who are not currently at increased risk.