In view of the high mortality of tetanus even when treated heroically with tetanus antitoxin, and because of experimental evidence that penicillin is effective against Clostridium tetani,1and since there is a scarcity of clinical reports on this subject, it is thought worth while to report the following 2 cases, both of which were treated with penicillin in addition to tetanus antitoxin: Case 1.— A Negro woman aged 22, seen as an office patient on June 14, 1944, complained of stiffness of the jaws for four days. She was treated expectantly but returned early the following morning with locked jaws and on June 15 was admitted to the hospital. She stated that she had noticed four days previously, for no apparent reason, stiffness of the body and pain in the back. This had gradually increased until a few hours prior to admission, when she became "stiff all over"