This study was conducted to determine the prevalence of substance use disorders in a geriatric psychiatry outpatient clinic. The overall prevalence for any substance use disorder was 20% (N = 28). The prevalence of benzodiazepine dependence was 11.4% (N = 16); the prevalence of alcohol dependence was 8.6% (N = 12); and the prevalence of prescription narcotic dependence was 1.4% (N = 2). These findings suggest that substance use disorders in the geriatric psychiatry outpatient population exist to a significantly greater extent than previously reported. Descriptive statistics were used to characterize patients with benzodiazepine dependence, alcohol dependence, and no substance use disorder. These groups were compared on demographic and clinical variables using one-way analysis of variance (ANOVA) and chi-squared statistical techniques. Clinicians working in comparable outpatient settings may be in a better position to prevent, detect, and treat substance use disorders in their patients as a result of increased awareness of its epidemiologic characteristics in this population.