Sleep disturbances are usually the outcome of a complex interplay between intrinsic factors and environmental influences. Cytokines are essential in the coordination of central nervous and immune system communication. Interleukin-1β and interleukin-6 in particular play crucial role in sleep regulation. In vitro studies have demonstrated that high-flux membranes avidly remove cytokines. Aim of this study was to investigate the correlation of insomnia with the aforementioned cytokines and the influence of mode of haemodialysis on sleep disorders in dialysis patients. Using Athens Insomnia Scale (AIS), sleeping profile of 35 subjects (23 male, 12 female, mean age 56.2±13.6 years) was evaluated. Twenty five patients underwent hemodialysis (HD) and the rest hemofiltration (HF) using high-flux membrane. No significant difference was observed between the two groups with respect to age, sex, family status, education, self-esteem, coffee and alcohol consumption, psychiatric history, hemodialysis time and laboratory parameters. HF group demonstrated significantly higher AIS scores compared to HD (12.4±6.5 and 4.3±4.7 respectively, p<0.001). The acute effect of hemodialysis on serum cytokine concentrations revealed a slight increase of post-dialysis cytokine levels in HD group (9.8±2.52 to 9.92±6.06 for IL1β and 11.02±4.83 to 11.3±3.78pg/dl for IL6 respectively), but a significant decrease in HF group (from 11.88±3.57 to 8.89±2.07 for IL1β and from 11.66±5.97 to 6.58±4.44pg/dl for IL6 respectively, p<0.05). Moreover, significant correlation has been found between AIS score and IL1β levels of all patients (r=0.42, p<0.01). In conclusion, it seems that the mode of hemodialysis, by affecting cytokine kinetics, could influence sleep quality and quantity in such patients.