In a randomized, parallel, double-blind study, lisinopril (n = 412) reduced systolic and diastolic blood pressure more than nifedipine did (n = 416) after ten weeks treatment in patients (40-70 years) with mild to moderate essential hypertension. Lisinopril was tolerated better than nifedipine, with fewer withdrawals. Adverse experiences reported after a general question on discomfort were significantly lower for lisinopril than for nifedipine. Questions referring specifically to symptoms revealed higher frequency of coughing with lisinopril, while flushing, edema, palpitations, dizziness, tiredness and rash were reported more frequently with nifedipine. Quality of life was similarly assessed by both patients and spouses. No significant differences in well-being during treatment were found for either drug, except in the case of the highest dose level of nifedipine, which caused a deterioration of well-being.