Therefore, this study aimed to investigate the association between the occurrence of <i>TPH1, TPH2, KAT1, KAT2</i> and <i>IDO1</i> polymorphisms and the risk of stroke development.The following 10 polymorphisms of the genes encoding enzymes of the TRYCATs pathway were selected: c.804-7C > A (rs10488682), c.-1668T > A (rs623580), c.803+221C > A (rs1800532), c.-173A > T (rs1799913) - <i>TPH1</i>, c.-1449C > A (rs7963803), and c.-844G > T (rs4570625) - <i>TPH2</i>. c.*456G > A of <i>KAT1</i> (rs10988134), c.975-7T > C of <i>KAT2</i> (rs1480544), c.-1849C > A (rs3824259) and c. -1493G > C (rs10089084) of <i>IDO1</i>.