OBJECTIVES: This study examined the prevalence of self-reported adherence to medications for osteoarthritis (OA) and racial differences in adherence. METHODS: This was a cross-sectional survey of 156 Black and White veterans who were taking medications for OA. RESULTS: One quarter of participants reported sometimes forgetting to take their OA medications, 16% were sometimes careless about taking medications, and 27% sometimes stopped taking their medications when they felt better. Overall, 44% of participants reported at least one of these three behaviors. In a multivariable logistic regression model adjusting for demographic factors, OA severity, participatory decision making (PDM), and side effects, Black patients were more likely to report at least one nonadherent behavior (odds ratio [OR] = 2.25, 95% CI = 1.03-4.91). Patients with greater PDM scores were slightly less likely to report nonadherent behavior (OR = 0.95, 95% CI = 0.91-0.99). DISCUSSION: Additional research is needed to examine factors underlying racial differences in adherence, to guide effective interventions.