Background:Stevens-Johnson syndrome is an uncommon, acute life-threatening disease characterized by extensive epidermal sloughing and mucositis. In childhood, as in adulthood, this condition is mostly related to drugs, in particular antibiotics. Only a few cases reported were firmly attributed to infectious agents, mainly Mycoplasma pneumonia but the causative role of infectious microorganisms seems particularly relevant in pediatric patients. The seriousness of this condition imposes a prompt recognition and the early withdrawal of the potential causative drugs or the institution of directed measures against infectious agents (depending on the suspected etiology), as well as a supportive and more specific therapy. Some treatments claim to halt the progression of skin detachment, but remain of unproven benefit due to the lack of prospective, well controlled, randomized clinical trials.Main observations:We report a case of a 2-year-old boy admitted in our hospital for the treatment of an ependymoma of the posterior fossa, who developed a Stevens-Johnson syndrome associated most probably with a cytomegalovirus infection. He was successfully treated with high dose intravenous immunoglobulin and gancyclovir.Conclusion:To the best of our knowledge, this is the first case of SJS associated with CMV infection