Multiple myeloma is a malignant neoplastic disease, characterized by uncontrolled proliferation and accumulation of plasma cells in the bone marrow, which is usually connected with production of a monoclonal protein. It is the second most common hematologic malignancy. It constitutes approximately 1% of all cancers and 10% of hematological malignancies. Despite the huge progress that has been made in the treatment of multiple myeloma in the past 30 years including the introduction of new immunomodulatory drugs and proteasome inhibitors, it is still an incurable disease. According to current data, the five-year survival rate is 45%. Multiple myeloma is a very heterogeneous disease with a very diverse clinical course, which is expressed by differences in effectiveness of therapeutic strategies and ability to develop chemoresistance. This diversity implies the need to define risk stratification factors that would help to create personalized and optimized therapy and thereby improve treatment outcomes. Prognostic markers that aim to objectively evaluate the risk of a poor outcome, relapse and the patient's overall outcome are useful for this purpose. The existing, widely used prognostic classifications, such as the Salmon-Durie classification or ISS, do not allow for individualization of treatment. As a result of the development of diagnostic techniques, especially cytogenetics and molecular biology, we were able to discover a lot of new, more sensitive and specific prognostic factors. The paper presents recent reports on the role of molecular, cytogenetic and biochemical alterations in pathogenesis and prognosis of the disease.