[en] Radiation grafting is a frequently used technique to modify some properties of the widely used natural polymer cellulose (e.g. water absorption capacity, dyeability). In this work the properties of cotton fibres grafted with a wide variety of monomers were investigated as a function of the irradiation dose, grafting conditions and chemical structure of the monomers. The grafting was performed using both the preirradiation and mutual grafting methods. Before grafting we studied the effect of irradiation on the cotton-cellulose used in the experiments. Samples were irradiated in air, at room temperature by 60^Co γ-rays up to 30 kGy dose. The degree of polymerization (DP) of the samples decreased from 1780 to 480 after 10 kGy irradiation. This change in DP did not result in a significant change in the tensile strength of the samples up to 30 kGy dose. No damage on the surface of the fibres was observed by using scanning electron microscopy even after 40 kGy irradiation. Preirradiation grafting: after irradiation the samples were immediately soaked in deoxygenated monomer solutions (water/methanol 80/20, in the case of 2-ethylhexyl acrylate pure methanol) at 40 degree for 1 hour with continuous stirring and nitrogen gas bubbling. The monomers used for grafting were acrylamide, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, N,N'-methylene bisacrylamide and 2-ethylhexyl acrylate. Mutual grafting: samples were soaked in deoxygenated monomer (N-vinyl pyrrolidone) or aqueous monomer solution (N-vinyl pyrrolidone or acrylamide) of different concentration containing also Mohr salt (to avoid homopolymerization) and irradieted in sealed glass ampulles at room temperature by 60^Co gamma rays up to 40 kGy dose (dose rate 15 kGy/h). SEM pictures clearly showed the formation of a coating layer on the fibres. The grafting yield was measured by the percent increase in the mass of the samples and also by FTIR spectroscopy. Optimum grafting conditions were determined by varying the monomer concentration, grafting time, irradiation temperature, and dose