<p><strong>Background:</strong> Multiple myeloma is characterized by abnormal plasmocytes proliferation in the bone marrow, resulting in an immunoglobulin oversecretion, which can cause bone pain, anemia, kidney dysfunction, and infections. The present study evaluates prognostic factors and the bone involvement in patients who had a confirmed diagnosis of MM.</p><p><strong>Methods:</strong> A retrospective study was conducted in hospital universitário São Francisco of Bragança Paulista. Patient demographic data, laboratory parameters and treatment received were recorded. We also analyzed the variables related to diagnosis and the development of bone lesions in MM patients.</p><p><strong>Results:</strong> A total of 42 patients had a confirmed diagnosis of MM, out of which most (54.76%) were older than 65. Most patients (45.24%) had beta-2-microglobulin values greater than 5.5 mcg/dl, indicating an advanced stage of the disease and consequently a less favorable prognosis. The main clinical manifestation observed was anemia in 61.90% (26/42) and bone lesions 59.52% (25/42). The analysis of imaging exams showed that most patients presented bone alterations, such as osteopenia, lytic lesions and fractures. Interestingly, 11.90% patients were submitted to autologous bone marrow transplantation with further remission of the disease. Bone marrow transplantation increases overall survival and disease-free survival when compared to conventional treatment.</p><p><strong>Conclusions:</strong> Since MM prognostic factors are numerous and, therefore, the understanding and analysis of the clinical and laboratory features of MM can contribute to an early diagnosis of patients, a targeted therapeutic approach and better outcomes.</p>