We have identified a previously unrecognized source of accidental drowning in infants and toddlers: 5-gal (19-L) industrial buckets. Twelve cases of drownings in these large-capacity buckets constituted 24% of all infant and toddler (age less than 3 years) drownings investigated by the Cook County (Illinois) Medical Examiner's Office from January 1985 to June 1989. The buckets, all with 5-gal and 18-kg capacity, are constructed of heavy, rigid plastic and are intended for industrial use. Home use, typically as mop buckets, was associated with the toddlers' death. The large size and heavy construction of these buckets as well as the toddlers' cephalad center of gravity and undeveloped coordination prohibit the toddlers from extricating themselves after peering into and falling inside the buckets. Parents and public health officials should be advised that domestic use of these containers poses a serious threat to the safety of curious toddlers. Adults should never leave toddlers unattended around even small amounts of water.