Sixteen incidents involving dog bites fitting the description "severe" were identified among 5,711 dog bite incidents reported to health departments in five South Carolina counties (population 750,912 in 1980) between July 1, 1979, and June 30, 1982. A "severe" attack was defined as one in which the dog "repeatedly bit or vigorously shook its victim, and the victim or the person intervening had extreme difficulty terminating the attack." Information from health department records was clarified by interviews with animal control officers, health and police officials, and persons with firsthand knowledge of the events. Investigation disclosed that the dogs involved in the 16 severe attacks were reproductively intact males. The median age of the dogs was 3 years. A majority of the attacks were by American Staffordshire terriers, St. Bernards, and cocker spaniels. Ten of the dogs had been aggressive toward people or other dogs before the incident that was investigated. Ten of the 16 victims of severe attacks were 10 years of age or younger; the median age of all 16 victims was 8 years. Twelve of the victims either were members of the family that owned the attacking dog or had had contact with the dog before the attack. Eleven of the victims were bitten on the head, neck, or shoulders. In 88 percent of the cases, the attacks took place in the owner's yard or home, or in the adjoining yard. In 10 of the 16 incidents, members of the victims' families witnessed the attacks. The characteristics of these attacks, only one of which proved fatal, were similar in many respects to those that have been reported for other dog bite incidents that resulted in fatalities. On the basis of this study, the author estimates that a risk of 2 fatalities per 1,000 reported dog bites may exist nationwide. Suggestions made for the prevention of severe attacks focus on changing the behavior of both potential canine attackers and potential victims.