The efficacy and tolerance of nicardipine were evaluated in 2184 ambulatory hypertensive patients with or without concomitant diseases in a 24-week Italian multicenter study. Of the total patient group 1083 had one or more concomitant diseases (diabetes mellitus, coronary heart disease, cardiac failure, mild renal failure, chronic cerebrovascular disease, obstructive lung disease, and peripheral vascular disease); of these patients, 419 were aged over 65 years. Patients were seen on an outpatient basis and after a 2- to 4-week washout period were admitted to the study. The initial nicardipine dose of 20 mg three times a day was titrated in subsequent weeks; thereafter a second antihypertensive drug was added if seated diastolic blood pressure was not reduced below 90 mm Hg. The nicardipine-based therapy significantly lowered seated blood pressure in the whole population (mean 185/102 to 152/86 mm Hg) without clinically and statistically significant differences between the patient subgroups with concomitant diseases. There were no changes in either symptoms, or biochemical and instrumental tests of the concomitant diseases. The incidence of side effects was low; in particular, there was no orthostatic hypotension. Nicardipine-based treatment is therefore effective, safe, and well tolerated in elderly hypertensive patients with concomitant disease.