Hydrophobically modified water-soluble polymers have been prepared by radical copolymerization of acrylamide and ethylphenylacrylamide as the hydrophobic comonomer. Three methods of synthesis in aqueous media have been investigated: (i) a «micellar» process in which the presence of a surfactant ensures the solubilization of the hydrophobic monomer; (ii) a «homogeneous» process wherein a miscible cosolvent is used; (iii) a «heterogeneous» process, without additive to solubilize the insoluble monomer. The properties of the copolymers in dilute and semidilute aqueous solutions strongly depend on the conditions of the synthesis