A 10-year-old black boy, a resident of East St. Louis, Ill, developed a solitary coccidioidal subcutaneous abscess almost two years after any known exposure to Coccidioides immitis. Clinical presentation and results of serologic determinations indicated that this lesion was the result of dissemination from a previous focus of infection rather than from cutaneous inoculation. The importance of certain clinical and laboratory criteria which aid in defining the pathogenesis of a subcutaneous coccidioidal lesion as well as the diagnostic and prognostic value of selected serologic tests are stressed.