A new and versatile synthesis was developed to produce polymer prodrugs composed of poly(2-methacryloyloxyethyl phosphorylcholine) (polyMPC) conjugated covalently to the glioblastoma drug Temozolomide (TMZ). Through a controlled free radical copolymerization of a TMZ-substituted methacrylate and MPC, water-soluble polyMPC-TMZ conjugates were realized with TMZ loadings of >50 mol %. After polymerization, the structural fidelity of the pendent TMZ moieties was confirmed by NMR and UV-vis spectroscopy, while molecular weight estimation by gel permeation chromatography (GPC) confirmed the desired control over the polymerization, with isolated polymer-TMZ conjugates exhibiting narrow molecular weight distributions. This synthetic design opens new possibilities for formulating numerous types of polymeric TMZ-based structures that are of interest for treating glioblastoma.