The viscoelastic behavior of monolayers of three polymeric amphiphiles with hydrophobic mesogenic side chains was observed by dynamic measurements. The copolymer with a long flexible and hydrophilic main chain between side chains exhibited very low values of viscosity and shear modulus at all accessible surface pressures. For the other two polymers with shorter segments of main chain between side chains these values increased steeply with compression through areas lower than 0.4 nm2 per monomer, reaching viscosities as high as 1 N s m-1 and shear moduli of 10 mN m-1.