OBJECTIVE The study aims to assess the quality of care provided at a diabetes outpatient clinic of a tertiary hospital in Nigeria using quality indicators approved by the National Diabetes Quality Improvement Alliance (NDQIA). METHODS The medical records of patients who had visited the clinic at least two times within a 12 months period preceding the index visit were reviewed during a 5 month period. Process measure indicators, approved by the NDQIA (evaluating the functioning of the clinic) and outcome measures, published by the American Diabetes Association, (evaluating the health status of the attending patients) were retrieved from the medical records. RESULTS The 332 records reviewed showed that the most consistently performed process measures were blood pressure and weight measurement (>90%). Foot examination was done infrequently (10.5%). Less than 50% had at least an annual low-density lipoprotein cholesterol (LDL-C) and hemoglobin A1c testing done. The mean (standard deviation) HbA1C (%), LDL-C (mg/dL) systolic blood pressure (SBP) (mmHg), and diastolic blood pressure (DBP) (mmHg) were 7.6 (2.0), 107.3 (31.5), 134.3 (20.8), 79.5 (11.0), respectively. HbA1C >8.0%, LDL-C >130 mg/dL, SBP >130 mmHg, and DBP >90 mmHg) were observed in 34.8%, 21.1%, 40.4%, and 23.8%, respectively. CONCLUSIONS Although the organization of the outpatient services allowed for good performance with regards to "free" services such as blood pressure and weight measurement, it performed suboptimally for foot examinations. Performance indicators that required payment were consistently underperformed. Regular assessment of the quality of care may help in the identification of opportunities for improvement in the organization and delivery of care.