Cough associated with angiotensin-converting enzyme (ACE) inhibitors has long been considered a rare side effect. We report 8 cases, 7 with enalapril (10 to 20 mg/day) 1 with quinapril (40 mg/day) in which cough occurred after a mean duration of treatment of 39 days. In all patients, cough disappeared with a mean delay of 2 days with no other treatment than withdrawal of the drug. In 6 patients, cough was reinduced within less than a day with the same drug; in 5 patients a second reinduction with another ACE inhibitor gave the same result. These data suggest that cough is probably more frequent than it would appear from the literature. In clinical practice, if cough occurs in a patient treated with an ACE inhibitor, the drug may be continued for a few days in order to exclude an acute viral infection; if cough lasts more than a week, specific diagnostic procedures for pulmonary disease should be initiated; if it stops, the patient may be treated either for hypertension or chronic heart failure with another ACE inhibitor.