By thermochemotherapy is meant the use of artificial fever to supplement the use of chemical agents in the treatment of infections. Our experience with a group of patients who received artificial fever in combination with sulfanilamide has convinced us of the value of such a plan of treatment. Patients chosen for thermochemotherapy at first were those who had failed to respond to artificial fever or those in whom the treatment with sulfanilamide had failed. When these agencies were administered simultaneously, however, it was soon seen that the combination of these remedies was more efficacious than when either was used alone. Urethral discharge and cloudy urine, due to the gonococcic infection, which had not responded to large doses of sulfanilamide, were seen to disappear in one or two days after thermochemotherapeusis. In these treatments 80 grains (5 Gm.) of sulfanilamide was given daily for two days; then artificial fever was administered.