Our present study was conducted to evaluate the role of the RANK (rs8086340, C > G; rs1805034, C > T) and RANKL (rs7325635, G > A; rs7988338 G > A) SNPs as potential diagnostic biomarkers associated with the RA risk in the Polish population, and prognostic biomarkers affecting the outcome of the biological treatment. This evidence concerns the gene TNFRSF11A and rheumatoid arthritis.