This study was conducted to investigate the therapeutic effect of verapamil, trandolapril and a fixed-dose combination of the two on blood pressure in essential hypertension (HT). 65 patients with essential hypertrension (33F, 32M) (mean age 50.3±8.1) were evaluated with 24-hour ambulatory blood pressure values. Patients were randomized to one of the 3 treatment protocols: verapamil SR 240 mg, trandolapril 2 mg, verapamil SR 180 mg + trandolapril 2 mg. Both clinical and ambulatory BP measurements were repeated on the 8th week of therapy. With trandolapril, verapamil SR and combination treatment clinical systolic and diastolic blood pressure (S/DBP) values decreased by 17.4/10.5, 15.0/9.3, 19.0/14.3 mmHg and 24-hour mean S/DBP by 14.4/11.5, 13.3/9.5, 17.4/12.1 mmHg. All three protocols were observed to be effective in mild to moderate HT treatment. Although there was no statistically significant difference between the results of the treatment protocols, a greater decrease in clinical and 24-hour mean BP values was observed in the combination treatment group. Hence, all three treatment protocols proved to be effective, and randomised studies with larger patient populations should be conducted to evaluate the effect of fixed-dose combination therapy in mild to moderate HT.