White sponge nevus is a rare, inherited disorder that usually presents as nonpainful white plaque primarily involving the buccal mucosa, gingiva, and palate. Extraoral lesions most often occur in the esophagus or anogenital area, but almost invariably follow the development of typical buccal lesions. This article presents a familial case of white sponge nevus in which oral lesions were found in patients in three generations of the same family. Histologic findings include hyperkeratosis, acanthosis, and perinuclear eosinophilic condensation of epithelial cell cytoplasm, which serve to confirm white sponge nevus as the diagnosis. Clinical presentation and histopathology of white sponge nevus are discussed in relation to the differential diagnosis of other oral leukokeratoses. Keywords: hereditary, hyperkeratosis, white lesion