We report on a 52-year-old patient with a typical manifestation of a haematogenous contact reaction. The characteristic distribution of light-red erythema predominantly located in the major flexural areas of the extremities and on the buttocks was consistent with the diagnosis of "baboon syndrome." The term derives from the skin lesions, which are compared to the red gluteal region of the baboon. An allergic type-IV reaction to systemically administered allergens probably underlies lesions of this type. In our case the baboon syndrome had been induced by amoxicillin. So far, mercury, nickel, ampicillin, and heparin have been reported as causes of baboon syndrome.