Poly-l-lactides containing β-alkyl α-malate-units were prepared by ring-opening copolymerizations of l-lactide with 3-(s)-[(benzyloxycarbonyl)methyl]- (BMD) and 3-(s)-[(dodecyloxycarbonyl)methyl]-1,4-dioxane-2,5-diones (DMD). The solution-cast films of these copolymers were alkali-treated to form a carboxyl-functionalized surface on which cell-binding Arg–Gly–Asp tripeptide (RGD) was immobilized with dicyclohexylcarbodiimide as coupling agent. For the copolymer of l-lactide and BMD the benzyl groups were removed by catalytic hydrogenolysis to obtain a fully carboxyl-functionalized copolymer (PLGM), and RGD was immobilized on the surface of its cast film. All the RGD-immobilized films thus prepared exhibited improved cell attachment compared with the original films. The cell attachment increased with increasing amount of immobilized RGD, which depended on the composition of the α-malate units in the copolymer. The RGD-immobilized PLGM films were degraded rapidly during the cell culture, while the RGD-immobilized films of the β-alkyl α-malate-containing polymers survived the cell culture with little degradation. The rate of hydrolysis increased with increasing content of α-malate units for both series, depending on the structure of the protecting groups of the β-carboxyl. These results suggest that the RGD-immobilized polymers could be a new class of functional bioresorbable polymer having improved cell-attachment and adjustable hydrolysis rate.