Background: Homelessness is a global phenomenon with considerable variations. Substance Abuse and Violence are significant problems among homeless youth, compared to the general population. Aim: This study aims to assess Substance Abuse and Violence among Homeless Youth in Fayoum Governorate. Study Design: : A descriptive research design was used for conducted this study. Setting: The study was conducted in Fayoum Governorate especiallly the greatest streets with the aid of Atfal Bala Maawa mobile units.Sample: Convenience sample was used in this study to collect data for about 3 months..Tools: Tool I:- Demographic characteristics of homeless youth, homeless youth knowledge regarding violence, homeless youth knowledge regarding substance abuse. Tool II:- Youth Risk Behavior SurveyResults: The presenting study showed that, 55.0% of homeless youth poor knowledge regarding violence, 30% of them had average knowledge, 15% of them had good knowledge regarding violence, 45.0% of the homeless youth poor knowledge regarding substance abuse, 35% of them average knowledge and 20% of them had good knowledge regarding substance abuse, 92.8% of them carring weapon, 71.5% of them hadn't physically forced to sexual assualt, 78.5% of them trying cigarette smoking. 14.2% of them trying drinking alcohol, 35.7% of them trying using marijuana during homeless youth life.