The authors describe 4 cases of multiple myeloma that developed one or more extraskeletal localizations. They have evaluated the relation between the onset of the extraskeletal localizations and the following myeloma characteristics: tumor burden, clinical phase, chemotherapy response, prognostic significance. All the patients showed these localizations in a plateau phase of myeloma. None of the patients had fever, pancytopenia and in no one the performance status worsened. All patients obtained at least a partial reduction of the localization and only the patient with the retro-orbital localization, got worse and died for myeloma. The other three patients are alive and do not show any sign of progression.