Background: Street youth are vulnerable to HIV/AIDS and all kinds of health risks. This study assessed HIV/AIDS risky sexual behaviors and its predictors among street youth in Gondar town, Northwest Ethiopia. Methods. A community based cross sectional study was conducted on 467 street youth living in Gondar town. A pre tested and structured questionnaire via interview was used to collect data. Logistic regression analysis was used to identify predictors. Odds ratio with 95% CI was computed to assess the strength of associations. Results: A total of 288 (61.7%) respondents had sexual intercourse in their life time. Among these 264 (91.7%) had more than one lifetime sexual partners. In addition, 80.5% of them used condom inconsistently in the last 12 months. Khat chewing was found to be predictor of having multiple sexual partners. Rural former residence and longer duration of stay on the street are also identified as predictors of inconsistent condom use. Conclusion: High prevalence of HIV/AIDS risky sexual behaviors were observed among street youth in Gondar town. Interventions aimed at reducing sexual risky behaviors among street youth should focus on reducing the duration of stay on the street and chat chewing.