Health Nurses in Agricultural Communities (OHNAC)* of Iowa identified a case of localized tetanus through active surveillance of emergency room records. A 46 year old horse owner incurred a flap laceration of the left thumb as he added concrete blocks to a drag used to even the ground in the horse arena. The wound was vigorously cleaned with soap and water, and he related having difficulty removing debris from the laceration. Stiffness in the thumb persisted for 8 days. During the course of the eighth day, tetany progressed up his arm into his shoulder and neck area. Physical examination showed decreased sensation over the distal two thirds of the left arm, hyper-reflexive deep tendon reflexes, and increased muscle tone of the left arm. Cerebellar function and gait were normal. Intramuscular injections of 3,000 IV of tetanus immune globulin and a tetanus-diphtheria booster were administered over seven sites. He reported primary childhood tetanus immunizations and a booster in December 1984. His recovery was complete and uneventful. Risk factors in this case include age, sex, warm weather, manure/soil environment, inability to completely clean