A clinical study of bromocriptine in the treatment of 18 patients with an unstable bladder is reported. All patients had previously received drug therapy and/or vesical distension, without success. Ten of the 18 patients had side-effects, and 2 of these did not complete the study. Only 2 patients noted moderate improvement in their urinary symptoms. Bromocriptine appears to be of little value in the treatment of the unstable bladder.