Individuals with substance use disorders are often plagued by psychiatric comorbidities and histories of physical and/or sexual trauma. Males and females, although different in their rates of expressed trauma and psychiatric symptomatology, experience comparable adverse consequences, including poorer substance abuse treatment outcomes, diminished psychosocial functioning, and severe employment problems. The goal of the current study was to examine the relationships between trauma history, lifetime endorsement of psychiatric symptoms, and gender in a sample of individuals participating in outpatient substance abuse treatment. Study participants (N = 625) from six psychosocial counseling and five methadone maintenance programs were recruited as part of a larger study conducted through the National Institute on Drug Abuse Clinical Trials Network (NIDA CTN). Study measures included lifetime trauma experience (yes/no), type of trauma experienced (sexual, physical, both), lifetime depression/anxiety, and lifetime suicidal thoughts/attempts (as measured by the Addiction Severity Index–Lite [ASI-Lite]). Lifetime endorsement of psychiatric symptoms was compared between individuals with and without trauma history. The role of gender was also examined. Results indicated that the experience of trauma was associated with an increase in lifetime report of psychiatric symptoms. Experience of physical and combined physical and sexual trauma consistently predicted positive report of psychiatric symptoms in both males and females, even when controlling for demographic and treatment-related variables. Employment outcomes, however, were not predicted by self-reported history of lifetime trauma.