Objective: We present the case of a patient with testicular plasmacytoma as initial presentation of multiple myeloma, and we carry out a literature review of this uncommon pathology. Methods: 63 year-old male who consulted for a testicular mass for three months. After clinical and diagnostic studies he underwent radical orchiectomy. Results: Pathologic study of the specimen revealed the presence of round cells, some with plasmocytic aspect. Immunohistochemical studies gave the final diagnosis of plasmacytoma. Studies on disease extension showed rounded lytic lesions spread over the vault of the skull bones. Bone marrow studies, as well as bone biopsy showed infiltration by plasma cell neoplasia in more than 90%, consistent with the diagnosis of multiple myeloma. The patient received treatment, developing disease progression and subsequently died from the disease. Conclusions: Solitary plasmacytoma represents only 6% of all plasma cell neoplasms. Testicular presentation is an unusual event, representing 2% of cases. Although this is usually an autopsy finding, it may constitute the first manifestation of multiple myeloma or exceptionally be the unique location of a plasma cell neoplasm. To date there are few reports published in the literature. This case constitutes a contribution for the knowledge of testicular plasmacytoma.