Most reported cases of Sotos syndrome are sporadic, but autosomal dominant and recessive inheritance patterns have been suggested. Ascertainment of a two-generation family through a 7-year-old proposita with a learning disability allowed the relatively unbiased study of two affected relatives. Developmental delay was not pronounced in the patient's mother or sister; craniofacial characteristics at variance with the characteristic description included acrocephaly and maxillary prominence. Steepness of the anterior cranial base angle and protrusion of the middle and lower face, shown in all three patients by cephalometric radiographs, deserve further evaluation as diagnostic criteria.