Between the plasma-cell neoplasms the solitary osseous plasmocitoma represents a low percentage of the whole totality. Unlike the multiple myeloma the plasmocytoma is a lesion potencially curable. The diagnose criteria that must fulfil these lesions are detailed. The AA. report a case sitting in the lower jaw. Review of the previous 28 cases communicated in the anglo-saxon literature. Special attention is paid to the radiotherapy on this sickness.