The iniferter technique was applied to synthesize a block copolymer of methacrylonitrile (MAN) and 2,3,3,4,4,4- hexafluorobutylmethacrylate (HFMA). Phenylazotriphenyl methane (PAT) was used as initiator for thermally initiated polymerization which proceeded via quasi-living radical mechanism. This was informed from the fact that yield and molecular weight (MnBAR) of the polymers increased with reaction time. The prepolymer obtained from one monomer was used as polymeric iniferter for the polymerization of the other monomer. This way block copolymers were obtained.