We surveyed 700 veterans who were outpatients in a non–Veterans Affairs (VA) multihospital system. Our objective was to assess the prevalence of mental disorders and service use among these veterans. The majority were Vietnam veterans (72.0%), and male (95.9%), and 40.4% reported recently using the VA for care. The prevalence of lifetime post-traumatic stress disorder (PTSD) was 9.6%, lifetime depression 18.4%, and lifetime mental health service use 50.1%. In multivariate analyses, significant factors associated with PTSD, depression, and mental health service use were low self-esteem, use of alcohol/drugs to cope, history of childhood adversity, high combat exposure, and low psychological resilience. VA service use was associated with greater mental health service use and combat exposure. With the exception of alcohol misuse, the mental health status of veterans seen in non-VA facilities appeared to be better than reported in past studies. Because most veterans have access to both VA and non-VA services, these findings have implications for veterans and outcomes research.