L-MYC and GSTMI polymorphisms were studied in glioma patients. L-MYC allele frequency in patients (L: 61/114 (54%); S: 53/114 (46%)) and controls (L: 108/204 (53%); S: 96/204 (47%)) was identical. S allele was associated with certain unfavourable clinical features of the disease. In particular, its frequency was 26/42 (62%) in relapse vs. 26/68 (38%) in relapse-free disease (p < 0.05). GSTMI "null" genotype was identified in both patients and healthy donors (48%). GSTMI-deficient genotypes were significantly predominant in patients with grade III-IV gliomas as compared with grade I-II tumors (p < 0.05). Patients, but not donors, frequently revealed a combination of SS L-MYC homozygosity and GSTMI (-) variant (p < 0.01) as well as an association of LL L0-MYC homozygosity and GSTMI (+) genotype (p < 0.05).