A review of the English-language medical literature revealed at least 70 cases of well-documented Mycoplasma pneumoniae infections associated with the Stevens-Johnson syndrome. There were no cases associated with erythema multiforme (von Hebra). Most of the patients were children and young adults, and male patients were more commonly affected. Most patients had prodromal symptoms of an upper respiratory tract infection before the onset of the eruption and an underlying pneumonia. Although the clinical course may be severe and prolonged, the prognosis is uniformly good with complete recovery in nearly all patients. Treatment is largely supportive and the use of antibiotics or steroids (or both) appears to have little effect on the course of the illness. We conclude that M. pneumoniae is the most common infectious agent associated with the Stevens-Johnson syndrome. It is not associated with erythema multiforme of von Hebra.