Malignant melanoma of the oral cavity is rare, accounting for about 1% to 8% of all melanomas. There have been no prospective studies of melanoma in this location, and all previous papers have reported small numbers of cases or have retrospectively reviewed case reports from the literature. The authors report six new cases and review 171 cases published since the last major review in 1975. The classification of oral melanomas with radial growth phases is discussed.