Background/Aims: Aims of the present study are to examine the effects of atorvastatin administration and the influence of membrane flux on adhesion molecules expression on monocytes. Methods: We studied CD11b, CD18 and CD62L expression on monocytes (flow cytometry) in 32 patients, 16 on low-flux (LFD) and 16 on high-flux (HFD) polysulfone hemodialysis, before and after dialysis and also after administration of atorvastatin 20 mg/day for 6 months. Results: After hemodialysis, expression of CD11b and CD18 increased and expression of CD62L decreased. After atorvastatin administration there was a decrease in pre-dialysis monocyte expression of CD11b and CD18, and an increase in the expression of CD62L compared to pre-dialysis baseline values. There were no statistically significant differences in expression of all three molecules between LFD and HFD groups. Conclusions: Polysulfone dialysis process activates monocytes irrespectively of the membrane flux. Atorvastatin use is associated with reduced monocyte activation.