The cases of three children diagnosed with baboon syndrome are described, being defined by the appearance of dermatological lesions, with characteristic distribution and morphology, as a result of having been in contact with mercury. Other substances have been described associated with the appearance of this syndrome; however their pathogenis is not completely known, and it has been suggested that it could be another form of contact dermatitis. Diagnosis is based on patient clinical history and physical examination and there is no specific treatment.