Results of a study conducted to assess the therapeutic effectiveness of systematic desensitization of erectile impotence are described. Three groups of eight patients each were formed. They were treated with systematic desensitization or conventional medication and general advice, or put on a waiting list. Therapeutic effects were investigated on the behavioral, subjective, and physiological levels. There were no significant differences among the three groups except on the subjective level. On this level, after therapy the systematic desensitization group rated feelings in sexually arousing situations as associated with significantly less anxiety than the other two groups. Systematic desensitization used alone as a treatment for erectile impotence shows only limited therapeutic effect. The unimproved patients were later treated using a modification of the Masters and Johnson technique. Early results suggest that this technique may be superior to systematic desensitization alone.