Drowning is the fourth leading cause of unintentional injury death in Los Angeles County. We examined data collected by the Los Angeles County Coroner's Office on drownings that occurred in the county from 1976 through 1984. There were 1587 drownings (1130 males and 457 females) during this nine-year period, for an annual rate of 2.36 drownings per 100,000 persons (3.44 for males and 1.33 for females). The largest proportion of drownings (44.5%) for both sexes, and in almost every age group, occurred in private swimming pools. Children 2 to 3 years of age had the highest swimming-pool drowning rate (7.95). The elderly also experienced high drowning rates, primarily in swimming pools and bathtubs. Drowning-site profiles varied dramatically by age and sex. These findings indicate a need for Los Angeles County to address the problem of drownings among infants and toddlers in private swimming pools and to investigate the failure of regulations requiring fencing of swimming pools to prevent these deaths. These findings also suggest several potential opportunities for preventive intervention by physicians and demonstrate that health professionals cannot rely on national drowning-site profiles when developing local drowning prevention strategies.