Tetanus was induced in rabbits by injection of high doses of purified tetanus toxin. After the induction of tetanus, the fasting blood glucose level was significantly elevated in the rabbits with tetanus--blood glucose level being 137.5 mg% compared with 114.8 mg% in controls. The Glucose tolerance showed the expected curve in control rabbits while in the rabbits with tetanus, there was a continuous rise in blood glucose levels even after 3 hours. Histological studies show degranulation of the beta cells of the pancreas in the tetanus rabbits. Thus, the high fasting blood sugar level and the diabetic pattern of Glucose tolerance observed in the tetanus animals are suggestive of reduced insulin production during tetanus, as part of the mechanism involved.