This single-blind, parallel-group, randomized trial compared the efficacy and tolerability of amlodipine with sustained-release nifedipine in 45 black African patients between the ages of 29 and 65 years. Amlodipine and nifedipine were administered after a 2-week washout period at a dose of 5 mg once daily and 20 mg twice daily, respectively. Dose was increased to 10 mg once daily for amlodipine and 40 mg twice daily for nifedipine in patients with diastolic blood pressure >90 mm Hg after 2 weeks. Treatment lasted for 12 weeks. Blood pressure was significantly reduced in both groups by week 12, with normalization rates of 75.0% for amlodipine and 72.2% for nifedipine. There was also a significant increase in heart rate in both groups by week 1 (heart rate in the erect position, +6.2 beats/min and +14.3 beats/min for amlodipine and nifedipine, respectively). No changes were observed in body weight or laboratory variables. Three patients in the nifedipine group withdrew from the study because of adverse effects (headache, two patients; severe palpitations/tachycardia, one patient). Other adverse effects, including pedal edema, frequent micturition, and dizziness, were mild and transient in most cases. Amlodipine and nifedipine have similar antihypertensive effects; amlodipine appeared to be better tolerated.