Synchronous or sequential development of multiple myeloma and prostate carcinoma is rare. It is not sure whether these two occur independently or if one influences the development of the other. We reviewed the cases published in the English literature; eight cases of myeloma developing after diagnosis and treatment for prostate carcinoma, five cases of simultaneous occurrence of myeloma and prostate carcinoma, and five cases where the patient with multiple myeloma later developed prostate carcinoma were found. This short review attempts to analyze the occurrence of these two diseases in the same patient and dissect whether there is a close association or it is just a mere coincidence.