Acute oral toxicity was evaluated in a single group of 16 Sprague-Dawley rats (8 male and 8 female) administered undiluted parachlorobenzotrifluoride by oral gavage in the amount of 5.0 ml/kg body weight. Mortality was observed in 2 males, and the LD50 value was estimated to be greater than 5 ml/kg in both males and females. Clinical observations included hypoactivity, tremors, ataxia, decreased limb tone, loss of righting reflex, blood on nose, lacrimation, hypothermia, hostility, and piloerection. The following observations were reported after gross necropsy of decedents and survivors: hemorrhagic areas in thymus; dark lungswith white foci; white foci on lungs; and a solid mass in the uterus of one female.