Twenty-four cases of solitary plasmacytoma of the mandible are reported in the literature. The criteria for the selection of cases and for their diagnosis are described. It is a rare condition, with a maximum occurrence in the fifth to seventh decades and a male to female ratio of 2:1. It predominates in the premolar and molar regions. Clinical and radiological features are non-specific. Diagnosis is by biopsy. Treatment of preference is surgery. Irradiation of greater than 5,000 Rads is also recommended. Investigations must be carried out for multiple myeloma. Long-term regular surveillance is advised, for infrequently, multiple myeloma may develop.