A previously healthy man developed an acute encephalopathy with coma after a single wasp sting on his chin. Brain CT showed bilateral pallidostriatal radio-lucencies. He died 72 hours after the sting with no evidence of primary cardiorespiratory failure or allergic reaction. Pathological findings were bilateral pallidostriatal necrosis and diffuse neuronal damage in the frontal, temporal, and parietal cortex. The neurotoxic effect of the poison, together with a hypersensitivity are the most likely explanations for this unusual encephalopathy.