In a previous study we have shown that vitamin C has some effect on the polymer surface by adsorption to it, which would probably affect the protein adsorption and platelet adhesion. The present work has been extended to demonstrate the influence of vitamin C on the kinetics of protein-polymer interaction, using labeled proteins, in the presence and absence of red blood cells, platelets and white blood cells. It appears that vitamin C causes an increase in albumin surface concentration compared to bare substrate which seems to decrease slightly in the presence of blood cells. On the other hand, the infusion of vitamin C to the fibrinogen blood cells system dramatically inhibits the fibrinogen surface binding. The role of L-ascorbic acid to reduce the protein adsorption in the presence of blood cells is discussed by taking into account (a) the interaction of vitamin C with the polymer surface, (b) the interaction of vitamin C with the proteins and cellular membrane, and (c) the interaction of proteins and cells with the polymer itself. The effect of various blood components also seems to be important, and slight differences in the adsorption pattern of proteins are observed in the presence of urea, creatinine, bilirubin, Fe+++ ion and zinc at normal blood levels.