To provide a profile of potential rescuers of cardiac arrest victims, 1,271 randomly selected subjects were interviewed by telephone. Thirty-nine percent had formal instruction in cardiopulmonary resuscitation (CPR), 90% knew the emergency telephone number (911), and 5% had performed CPR. Subjects with training were significantly younger than those without (36 vs 48 years old) (P less than .001), and they had a lower incidence of known heart disease in family members (7% vs 15%) (P less than .001). More men than women were trained in CPR (44% vs 37%) (P less than .015). We recommend that efforts be undertaken to reach target groups of middle-age and older women for CPR training, and that physicians assume an active role in encouraging families of cardiac patients to learn this procedure.