The clinical efficacy of oral clomipramine and amitriptyline treatment (50--125 mg/day) was compared over a period of 2 months in 72 depressive patients visiting a psychiatric out-patient clinic. Both drugs were equally effective as measured by the Hamilton Rating Scale for Depression. According to a nurse's independent evaluation of 13 items the two drugs were equipotent in relieving depressive symptoms and no statistically significant differences between the treatment groups were found in the global evaluation by the investigator and the patient. A trend in favour of clomipramine was, however, seen in several parameters. The declines in the Hamilton Rating Scale scores and the nurse's evaluation scores were highly significant during the first 2 weeks of treatment (P less than 0.001) in both groups and the scores continued to decrease during the 2nd month of the study. The most common unwanted effects were dryness of the mouth and fatigue. The frequency of side effects was 51% in the clomipramine group and 43% in the amitriptyline group. The side effects were generally mild and transient and called for discontinuation of treatment in only one case in each group.