The aim of this study was the investigation of HSA properties and its structural changes after modification induced in vivo among patients with CRF who underwent haemodialysis. Application of different fluorescent dyes allowed the investigation of different regions of albumin molecule using ANS, bis-ANS, piren, piren maleimide and fluorescein isothiocyanate. As markers of oxidative modification, the total protein thiol, carbonyls, glycosylated plasma proteins and hydroperoxide were estimated in plasma. Additionally, this study investigated plasma viscosity and total antioxidant capacity (TAC) of the plasma. Results show that haemodialysis provoked significant changes in conformational properties of plasma albumin, which resulted in the loss of its biological functions. These findings suggest that oxidative stress and glycation of proteins in plasma are developed during haemodialysis. The results depict that one of the features of uraemia is the presence of signs of oxidative stress before haemodialysis. Nevertheless, oxidative stress and glycation of proteins in plasma are exacerbated during haemodialysis and are a complex process.