OBJECTIVE—To evaluate ethnic differences in medication concerns (e.g., side effects and costs) that may contribute to ethnic differences in the adoption of and adherence to type 2 diabetes treatments.RESEARCH DESIGN AND METHODS—We conducted face-to-face interviews from May 2004 to May 2006 with type 2 diabetic patients ≥18 years of age (N = 676; 25% Latino, 34% non-Hispanic Caucasian, and 41% non-Hispanic African American) attending Chicago-area clinics. Primary outcomes of interest were concerns regarding medications and willingness to take additional medications.RESULTS—Latinos and African Americans had higher A1C levels than Caucasians (7.69 and 7.54% vs. 7.18%, respectively; P < 0.01). Latinos and African Americans were more likely than Caucasians to worry about drug side effects (66 and 49% vs. 39%, respectively) and medication dependency (65 and 52% vs. 39%, respectively; both P < 0.01). Ethnic minorities were also more likely to report reluctance to adding medications to their regimen (Latino 12%, African American 18%, and Caucasian 7%; P < 0.01). In analyses adjusted for demographics, income, education, and diabetes duration, current report of pain/discomfort with pills (odds ratio 2.43 [95% CI 1.39–4.27]), concern regarding disruption of daily routine (1.97 [1.14–3.42]), and African American ethnicity (2.48 [1.32–4.69]) emerged as major predictors of expressed reluctance to adding medications.CONCLUSIONS—Latinos and African Americans had significantly more concerns regarding the quality-of-life effects of diabetes-related medications than Caucasians. Whether these medication concerns contribute significantly to differences in treatment adoption and disparities in care deserves further exploration.