Purpose: This article systematically reviews studies of prevalence of childhood experience of physical and sexual abuse in adult people who are homeless in Western countries.Methods: Medline, PsychInfo, and the Cochrane Library were searched using the keywords: homeless*, child* abuse, child* trauma, and child* adversity and the bibliographies of identified articles were reviewed. Sources of heterogeneity in the prevalence rates were explored by meta-regression analysis Results: Twenty-four reports published between January 1990 and August 2013 in three countries provided estimates obtained from up to 9,730 adult individuals who were homeless.Prevalence of reported childhood physical abuse ranged from 6 to 94% with average prevalence of 37%, 95% CI [25, 51]. Reported sexual abuse ranged from 4 to 62%, with average prevalence estimated as 32%, 95% CI [23, 44] for females and 10% for males, 95% CI [6,17]. Substantial heterogeneity was observed among the studies (I 2 ≥ 98%). Including moderators greatly reduced but did not eliminate this heterogeneity. Moderator analyses suggested that reported physical abuse tended to be higher for predominately white samples and tended to be lower for younger samples. Sexual abuse was far more prevalent in predominately female samples and slightly higher in non-US samples and convenience samples.Conclusions: The findings of this study suggest that childhood physical and sexual abuse is more prevalent among the homeless in Western countries than in the global population. Physical abuse appears to be particularly prevalent in younger samples and sexual abuse rates are higher in predominately female samples. Further investigation is needed to advance our understanding of how trauma informed treatment and care for the homeless effectively can take into account the service user's experiences of childhood abuse.