One percent lindane, widely used to treat scabies and pediculosis, presents toxicologic problems when used excessively. A 16-year-old mentally retarded boy accidentally ingested approximately 392 g of 1% lindane shampoo and recovered. A 2-month-old, 4.5-kg, male infant was found dead in his crib after excessive application of a 1% lindane lotion. In the former patient, initial serum levels of lindane were 206 parts per billion (ppb) declining to 1.0 ppb after 25 days. In the latter, lindane was identified in the brain at a concentration of 110 ppb. Brain levels of lindane were three times greater than the levels found in the blood. Although the relationship of this pesticide exposure to the fatal outcome in the second case was conjectural, it was illustrative of the problem of interpreting CNS events that occur shortly after excessive exposure to this insecticide.