The-174G alpha-->C polymorphism of the interleukin 6 (IL-6) gene promoter and the-308G alpha-->A polymorphism of the tumor necrosis factor alpha (TNF alpha) gene promoter were tested for association with multiple myeloma (MM) varying in severity. Of 69 patients, 19 had aggressive MM, 26 had benign MM, and 24 had unidentified MM. The control group (N = 102) matched the test group in age and sex composition. The two groups did not significantly differ in allele and genotype frequencies of the IL-6 and TNF alpha genes. Genotype CC, which determines low-level expression of IL-6, occurred at a frequency of 0.35 in patients with low-progressing MM and was absent from patients with aggressive MM. The TNF alpha gene showed no association with predisposition to MM or clinical variant of the disease. On this evidence, the polymorphic variants of the cytokine genes were assumed to have no effect on predisposition to MM. As for MM progression, genotype CC of the IL-6 gene was associated with milder clinical signs in patients from Bashkortostan.