Melanoacanthoma is a simultaneous benign proliferation of two cell types--the keratinocyte and the melanocyte. It is a rare lesion; only twenty cases have been reported on skin and three cases intraorally. This article reports a series of ten cases of intraoral melanoacanthoma. Significant clinical differences exist between skin and mucosal lesions. Whereas the skin lesions occur almost exclusively in white persons and in an older population, the mucosal melanoacanthoma occurs in a much younger population, is seen almost exclusively among blacks, and is frequently associated with a history of trauma or irritation which precedes the rapid development of the lesion. Several cases have resolved with incomplete removal. It is conjectured that this lesion may represent a reactive phenomenon on oral mucosa rather than neoplasia.