The purpose of this study was to test the generalizability of previous research on gender differences between men and women with co-occurring schizophrenia and substance abuse. One hundred eight patients with schizophrenia or schizo-affective disorder involved in a study of treatment for homeless persons were interviewed for information regarding substance use, social functioning and support, comorbid disorders, victimization, medical illness, and legal troubles. We found that women had more children and were more socially connected than men. Women also had higher rates of sexual and physical victimization, comorbid anxiety and depression, and medical illness than men. We conclude that homeless women with dual disorders, like women with substance use disorders in the general population, have distinct characteristics, vulnerabilities, and treatment needs compared with men. In addition to comprehensive treatment of psychiatric and substance use disorders, gender-specific services should be developed, including prevention and treatment of victimization and related problems as well as help with accessing medical services.