The purpose of this study was to determine the effect of a motivational interviewing intervention (MII) on regimen adherence and diabetes markers among African Americans with diabetes. Sixty-two participants were assigned to the usual care (UC; n = 36) or MII (n = 26) groups. UC participants received the usual clinic care. MII participants received a maximum of six motivational interviewing (MI) sessions over 3 months. Outcome variables were obtained at baseline and 3-month follow-up. Data were obtained using medical records, self-reports, and glucose monitor and accelerometer print-outs. MII significantly increased the odds of participants adhering to recommended physical activity level (66.7% vs. 38.8%, odds ratio = 2.92, 95% confidence interval = [1.6, 14.3], p = .018) and significantly decreased glucose levels (p = .043) and body mass index (p = .046) over time when compared with UC. Findings support using MI as an intervention for improving health outcomes and regimen adherence rates among the study population.