This study compared methadone maintenance patients with and without pathological gambling (n = 167). Participants completed a self-report survey assessing lifetime pathological gambling and past-2-month gambling behavior, and they completed the SF-12v2 Health Survey, a measure of current mental and physical health. In the sample, 52.7% were classified as lifetime pathological gamblers, and the majority of pathological gamblers were actively gambling within the past 2 months. Multivariate analysis of covariance revealed that methadone maintenance patients with pathological gambling had significantly poorer mental and physical health than methadone maintenance patients without pathological gambling. These results suggest that pathological gamblers receiving methadone maintenance may benefit from additional psychosocial services. In fact, most pathological gamblers in the sample expressed interest in gambling-related services. These results extend previous research in other populations that has found that pathological gamblers report poorer mental and physical health than nonpathological gamblers.