Sixty patients suffering from mixed anxiety depressive states were admitted to a comparative controlled clinical trial of a free combination of opipramol 50 mg and clomipramine 10 mg and clomipramine 25 mg. A double-dummy technique was used to ensure blindness and both regimes were administered three times daily. A stratified randomization technique was employed but this did not work effectively as far as severity was concerned producing some imbalance in the groups. Thirty-one patients received the combination therapy and 29 clomipramine alone. Twenty-eight patients on the combination regime and 24 on clomipramine alone completed the study. Amongst the completers the total score, on a 17 symptom rating scale, fell from 19·6 to 6·6 in the combination group and from 23·6 to 9·3 in the clomipramine alone group after 4 weeks treatment. Significantly more side-effects, especially dry mouth, were seen in the clomipramine alone group. After 2 weeks the opipramol/clomipramine regime was significantly more effective in the relief of anxiety whereas the clomipramine higher dose regime brought about a significantly greater improvement in the symptom depressed mood.