A 14-year-old boy was seen because of irritability, insomnia, lethargy, and profusesweating, together with hypertension (blood pressure: 160/120 mm Hg), tachycardia, and a diffuse erythematous rash with desquamation of the palms and soles. Initial biochemical investigation suggested a diagnosis of pheochromocytoma, but subsequently a history of exposure to mercury vapor was obtained. This case emphasizes the clinical and blochemical similarities between mercury poisoning (acrodynia) and pheochromocytoma.