"Epidermal nevus syndrome" ("ENS") is a neurocutaneous disorder in which epidermal nevi are associated with other abnormalities, most commonly of the skeletal and central nervous systems. We present two cases of epidermal nevus syndrome (ENS) with very different clinical findings. The first case is a newborn with multiple linear epidermal nevi of the trunk and limbs, and several other anomalies, including bony duplications of the lower limbs and hypoplastic left heart syndrome. The second patient, a 6-year-old boy, has a linear nevus sebaceous of the scalp with severe CNS involvement, including generalized seizures, moderate mental retardation, microcephaly, and a left hemiparesis. He also has genitourinary, cardiac, and skeletal defects. These two patients exhibit several abnormalities not previously recognized and illustrate the wide clinical spectrum of "epidermal nevus syndrome." We present a review of the clinical findings in 74 cases of "ENS." Correlation was noted between the presence of skin lesions located on the head and CNS involvement. The wide clinical spectrum of "ENS" as illustrated by these two patients suggests that "ENS" is a causally heterogeneous group of disorders.