1. Reports in the literature of the use of hematoporphyrin in the depressed psychoses were for the most part favorable.2. There are by no means clear theories as to the physiological action of the drug.3. Experiments with laboratory animals indicated a definite influence on the weight and an increased response to stimuli.4. Laboratory studies had shown a tendency of the drug to elevate the blood count and to reduce the calcium level.5. Fourteen patients in all were treated adequately with hematoporphyrin.6. Two patients responded well, one of whom relapsed after a period of six weeks. The other continued to adjust on a low level.7. Laboratory examinations failed to disclose any specific influence on the blood picture except a tendency to lowered cholesterol levels.8. Our results do not warrant the use of this therapy in preference to any of the old armamentarium used in the treatment of depressed psychoses.9. The use of this drug did not produce any deleterious toxic reaction.