Objective: This study examines how emotion regulation deficits in the area of anger arousal and reactivity are associated with child abuse potential in mothers with substance use and depressive disorders in order to identify targeted areas for prevention and treatment. Methods: A sample of 152 urban mothers was interviewed on measures of substance use, diagnosis of depression, anger arousal and reactivity, and child abuse potential. Results: Linear hierarchical regressions revealed that anger arousal and reactivity exceeded diagnostic and demographic variables in predicting maternal child abuse potential. Additionally, anger arousal and reactivity was found to be a partial mediator of the relationship between diagnostic category and child abuse potential. Conclusions: Findings are discussed in relation to a multifaceted model of child abuse potential which broadens the existing literature to include an examination of depression and emotion regulation in order to more fully understand how substance use and child abuse potential are linked. Practice implications: Models and approaches which help clients to manage and regulate difficult feeling states, specifically anger, could be helpful, and may be most readily applied in such populations. (Contains 2 tables.)