Three children from Turkey were observed, showing an unusual hyperplasia of their oral mucosa, corresponding to focal epithelial hyperplasia (FEH), described by Heck. These are the first cases of Heck’s disease registered in the Federal Republic of Germany. The lesions in FEH are multiple, painless, soft papules of the oral mucosa. In all cases the lower lip was involved. The etiology of this rare condition is still unknown. Our investigations with electron microscope failed to confirm the presence of a virus in the lesions. Local application of vitamin A acid seems justified, since the lesions disappeared after this treatment in two cases. Spontaneous remissions are recorde