Two cases are described which presented with diffuse swelling of one cheek and hypertrophy of the underlying maxilla and mandible. Both children developed verrucous pigmented streaks over the area of swelling, and had epilepsy and severe mental subnormality. One of the children had a contralateral hemiplegia and his condition had a progressive course. The other child had no focal neurological signs and his disease seemed to be non-progressive. Although the facial appearance of both children suggested the diagnosis of encephalocrainiocutaneous lipomatosis syndrome, it was not possible to demonstrate the presence of any lipomata in either case. The literature relating to encephalocraniocutaneous lipomatosis is reviewed, as well as that relating to the syndromes of naevus unius lateris, the Proteus syndrome and the syndrome of cranial hemihypertrophy, and the clinical features of our two cases are compared with the features of these four syndromes.