Submersion injuries of children younger than 5 years in 4 urban Utah counties from 1984 through 1988 were studied retrospectively to identify associated risk factors. Infants younger than 1 year had the highest rates of both submersion injuries and deaths. The incidence of bathtub drownings was 2 to 3 times higher than reported national rates. All bathtub drownings occurred while the victim was bathing with a young sibling (10 months to 7 years of age) without adult supervision. All drownings in pools and moving bodies of water (rivers, irrigation ditches) resulted from unintentional falls into the water rather than from swimming and wading activities. Drowning prevention strategies should focus on educating parents about the risk of young children bathing with siblings in the absence of adult supervision and fencing regulations for pools and open bodies of moving water.