Infantile myofibromatosis, both solitary and multicentric types, is discussed with emphasis on the importance of diagnosing this condition correctly. Its distinctive clinical and histological characteristics are described, as are the hazards of overhasty and overly ambitious surgical intervention. Other similarly presenting fibromatous diseases of infancy and childhood are discussed, including aplasia cutis, infantile fibrosarcoma, recurring infantile digital fibromatosis, and juvenile aponeurotic fibromatosis. A case of infantile myofibromatosis, solitary type, is reported, and the two surgical procedures carried out over a 4-year period are described. The importance of histological and immunohistochemical evaluation of lesions present during the neonatal period is stressed.