['The aim of this study was to evaluate the changes in the levels of vasoactive eicosanoid hormone-like substances PGE2, PGI2 and TXA2 in hemodialysis (HD)patients who were following a long-term physical training program during the hemodialysis session.', 'A total of 50 patients with Chronic Kidney Disease (CKD) (stage 5)on hemodialysis and 35 healthy individuals who served as controls (C) were evaluated. The 50 CKD patients were divided into two groups: the HD group consisted of 31 patients who received usual care without any physical activity during the hemodialysis sessions, while group HD/Exer included 19 patients who followed a program of physical exercise for six months. Plasma levels of PGE2, 6-Keto-PGF1alpha (the stable derivative of PGI2) and TXB2 (the stable derivative of TXA2) were measured by reliable enzymo-immunoassay methods (EIA) in HD and HD/Exer patients before and after the hemodialysis sessions as well as in the group of C.', 'The plasma levels of PGE2 and 6-keto-PGF1alpha in group HD Exer/before patients were higher than those in group HDbefore (20.39+/-5.82 and 1449.19+/-553.41 vs 17.68+/-5.36 and 1295.10+/-384.43 pg/ml, p=0.044 and p=0.067, respectively), while the plasma levels of TXB2 were lower in HD Exer/before patients compared to HDbefore(499.76+/-67.51 vs 608.01+/-80.23 pg/ml, p=0.041). The plasma levels of PGE2 and 6-keto-PGF1alpha in group HD Exer/after patients were significantly higher compared to those in HDafter patients (23.01+/-5.70 and 1618.19+/-435.07 vs 16.57+/-4.97 and 1005.44+/-317.16 pg/ml, p<0.001 and p<0.040, respectively). However, significantly lower values in the plasma levels of TXB2 in HD Exer/after compared to HDafter patients (363.10+/-51.91 vs 439.75+/-62.34 pg/ml, p=0.030) were detected. As expected, PGE2 and 6-keto-PGF1alpha values were lower in C than in the groups of patients with CKD.'] Does physical training in patients on hemodialysis have a beneficial effect on the levels of eicosanoid hormone-like substances?