Poly(allyl methacrylate) (PAMA) and random copolymers of styrene (St) with allyl methacrylate (AMA) were prepared via atom transfer radical polymerization. For the homopolymerization of AMA, the maximum conversion depends on the reaction conditions and on the monomer/initiator ratio. For the copolymerization, AMA conversions of up to 90% were obtained while no cross-linking occurred. Kinetic studies of the homopolymerization revealed a controlled polymerization up to a certain conversion whereas at higher conversions, multimodal molecular weight distributions caused by branching reactions and cross-linking were observed. The copolymerization of AMA with St allowed a controlled reaction up to conversions higher than 90%. The copolymers obtained were soluble in standard organic solvents. In a subsequent reaction, these copolymers were cross-linked both thermally and photochemically using suitable initiators. Moreover, pendant double bonds were brominated quantitatively.