This study analyzed 20,764 exposures involving insect repellants containing N,N-diethyl-m-toluamide (DEET) that were reported to poison control centers from 1993 to 1997. Nearly 70% of the cases reported no symptoms related to the exposure. The occurrence of symptoms was related to the route of exposure, with the highest rates associated with ocular exposures, followed by inhalation, multiple exposure routes, dermal, and ingestion. Two deaths were reported, one in a 26-year-old male and one in a 34-year-old female, both following a dermal exposure. Twenty-six subjects experienced major effects. The greatest number of reported exposures involved infants and children, but this group experienced lower rates of adverse effects than teens or adults. There was no clear relationship between DEET concentration and presence or severity of clinical effects. For the cases reported to poison control centers and included in this analysis, the risk of serious medical effects for labeled use of insect repellants containing N,N-diethyl-m-toluamide appears to be low.