Multiple myeloma (MM) is a malignant disease of plasma cells with complex etiopathogenesis, causing significant morbidity due to multi-organ damage. Changes in the genes encoding transport proteins, resulting in changes in their function, affect the cell defense potential and response to the chemotherapy applied. The aim of this study was to determine the A388G single nucleotide polymorphism (SNP) in the SLCO1B1 gene in Polish multiple myeloma patients. The material for the study included DNA isolated from nucleus cells of peripheral blood in patients diagnosed with multiple myeloma. Clinicopathological characteristics, treatment processes, laboratory findings, and treatment outcomes were summarized and statistically analyzed. The studied polymorphism does not seem to affect the increased risk of development or treatment outcomes of multiple myeloma. Our research primarily focuses on investigating the association of transporter polymorphisms with multiple myeloma and providing theoretical evidence. Further studies are needed to better understand molecular mechanisms underlying an altered function of organic anion transporting polypeptides (OATPs) in MM.