Objective - The aim of the study was to investigate the relationship of the alleles and genotypes of the immune response mediator genes polymorphic loci (rs1800629, rs909253, rs16944, rs6822844, rs2104286, rs1800795, rs1800872, rs3087243, rs755622 rs28362491, rs2240336, rs2476601) with the etanercept efficacy in juvenile idiopathic arthritis (JIA) patients. Material and Methods - The study included 39 JIA patients from Bashkortostan, Russia. Achieving the American College of Rheumatology Pediatric 70 (ACR Pedi 70) response was regarded as the presence of the response to etanercept (otherwise - as the absence), while achieving clinical remission on medication - as the sufficient response (otherwise - as the insufficient). Genotyping was performed using real-time polymerase chain reaction method. Results - The predictors of an increased risk of the non-response to etanercept were the IL1B rs16944*TT (pcor=0.023), NFKB1 rs28362491*II (pcor=0.042) genotypes, and of the increased risk of the insufficient response to etanercept - the IL2RA rs2104286*AA (pcor=0.010), NFKB1 rs28362491*II (pcor=0.026) genotypes. The markers of the decreased risk of the non-response to etanercept were the IL1B rs16944*C (pcor=0.046), NFKB1 rs28362491*D (pcor=0.029) alleles, and of the decreased risk of the insufficient response to etanercept - the IL2RA rs2104286*AG genotype (pcor=0.049), IL2RA rs2104286*G allele (pcor=0.005). Conclusion - In this study the association of the alleles and genotypes of the IL1B rs16944, IL2RA rs2104286, NFKB1 rs28362491 polymorphic loci with the etanercept efficacy in JIA patients was established. © 2017, Nazarova L.S., Danilko K.V., Malievsky V.A., Bakirov A.B., Viktorova T.V.