In a survey including 2224 patients with essential hypertension we investigated efficacy and tolerability of the new ACE-inhibitor Imidapril. Mean blood pressure at baseline was 172 +/- 19/98 +/- 10 mm Hg. Treatment with Imidapril 5-20 mg once daily caused a decrease in BP by 21 17/11 +/- 10 mm. Hg (p < 0.01/0.01). Systolic BP was reduced by > 15 mm. Hg in 71 % diastolic BP by > 10 mm Hg in 64 % of patients. 29 % of patients achieved the treatment goal of a blood pressure < 140/90 within an average of 26 days. Imidapril decreased pulse-pressure (one of the most important risk markers in hypertension) by 18 % (74 17 to 61 +/- 11 mmHg, p < 0.01). ACE-inhibtor related adverse effects (cough, vertigo, headache, pruritus, tachycardia, orthostatic dysregulation or nausea) were observed in 38 patients (< 2 %). Efficacy of treatment was graded by the physician in charge of the patient care by means of a questionnaire. Gradings were excellent or good in 96 % of patients, moderate in 3% and poor in <1%. In summary, the effects of Imidapril on blood pressure were comparable to those of other ACE-inhibitors. However, the frequency of adverse effects was low and similar to that of angiotensin-II-antagonists.