Alternatives to lithium are desirable in the prophylaxis of affective disorders, especially in patients who are intolerant of or do not respond to that drug. In the past few years the anticonvulsant carbamazepine has been in the foreground of discussion. Twenty-four patients with affective disorders (17 unipolar depressed, six bipolar, and one unipolar manic) were included in a comparative trial of lithium and carbamazepine; 12 had been pretreated with lithium without a satisfactory effect. All patients received carbamazepine (four received it in combination with lithium) over a mean time span of 20.2 months. Eighty percent of the patients improved with carbamazepine treatment. Side effects were infrequent.