Two hundred forty-seven [142 women (57.49%)] elderly patients with essential hypertension (diastolic blood pressure between 95 and 114 mm Hg) and an average age of 67.4 +/- 6 years were included in an open multicenter ambulatory trial. One hundred thirty-seven had some kind of associated disease. After a 15-day washout period, the patients began nitrendipine therapy (10 mg o.d.). After 1 month, the dose was increased to 20 mg o.d. in patients with diastolic blood pressure (DPB) greater than or equal to 95 mm Hg, and thereafter 5 and 10 mg o.d. of bisoprolol was added to the maximal dose of nitrendipine (20 mg o.d.) in the case of patients with DBP greater than or equal to 95 mm Hg at the end of the second and third months, respectively. At the end of the 6-month follow-up period, the systolic and diastolic pressures had dropped -35 and -21 mm Hg, respectively, without any change in heart rate or Quetelet index. In 210 patients (84.9%), blood pressure control was achieved: 26 (10.5%) with 10 mg of nitrendipine, 149 (60.3%) with 20 mg of nitrendipine, and 35 (14.1%) by adding bisoprolol. The lipid profile, glucose, potassium, uric acid, or creatinine did not change negatively. Sixty-six (26.72%) patients reported clinical side effects, although these were mild; only 15 (6.07%) patients were excluded because of side effects. Nitrendipine has been shown to have a high therapeutic efficacy and biochemical tolerance for first-line treatment of elderly patients with mild-to-moderate essential hypertension with or without associated diseases.