Background: Chronic kidney disease (CKD) is one of the most frequently occurring diseases. A side effect of dialysis is, among other things, platelet activation. Arachidonic acid (AA) derivatives are released from activated platelets. In addition to being involved in many physical processes, they are also involved in the development of inflammation, asthma, cancer, diabetes, hypertension, and the pathogenesis of kidney disease. The aim of the study was to determine the concentrations of arachidonic acid (AA) derivatives (TXB 2 ,5-HETE, 12-HETE, 15-HETE), in patients with CKD.Methods:117 patients were qualified to the study group. Based on the type of renal replacement therapy, patients are divided into the following groups: hemodialysis, peritoneal dialysis, kidney transplant patients and conservative treatment (30; 30; 27; 30 patients). The control group consisted of 30 healthy volunteers. The concentrations of TXB 2 , 5-HETE, 12-HETE, 15-HETE, in the blood serum was measured by ELISA methods.Results: It was shown that renal replacement therapy significantly influences the concentration of TXB 2 p=0,010 5-HETE p<0,001 and 15-HETE p<0,001). There was a relationship between the type of renal replacement therapy and the duration of dialysis, and the concentration of TXB 2 , 12-HETE acid, and 15-HETE (p<0,001; p<0,001;p<0,001).Conclusions: The type of renal replacement therapy used had an effect on the concentration of arachidonic acid derivatives (TXB2, 5-HETE and 15-HETE). Apart from the type of therapy used in CKD patients, the factors significantly affecting the release of arachidonic acid derivatives were the age of patients, the duration of dialysis, the cause of CKD, and the stage of its advancement.