We treated 38 consecutive outpatients with ureter colic with a new anticholinergic spasmolytic agent, cimetropium bromide, in order to evaluate its efficacy in this condition. After assessing pain intensity by means of a visual analogic scale, we administered 5 mg i.v. Already after 30 minutes, 4 patients (11%) reported complete subsidence of pain. In 21 patients (55%) pain subsided almost completely within one hour. Eighteen patients required a second 5 mg i.v. injection after one hour; of these, 13 (72%) had complete regression or marked reduction of pain. Apart from dryness of the mouth which appeared in two cases after the second injection and was of moderate intensity, no side effects were observed.