In order to study the tacticity effect of the backbone on the thermotropic properties of side-chain Liquid crystalline (SCLC) polymers, the synthesis of four polymethacrylates with different tacticities and bearing methoxy biphenyl mesogenic groups was carried out. Homopolymers were obtained upon photopolymerisation at low temperature of two mesogenic methoxy biphenyl monomers, with and without ethylene oxide spacer. Methacrylic acid copolymers were obtained by grafting the same mesogenic groups onto 92% syndiotactic or atactic polymethacrylic acids. It is demonstrated that an increase of 11% of the content of syndiotactic triads compared to an atactic structure, does not modify the liquid crystal behavior of homopolymers. Indeed, smectic OB, A, E and nematic phases were identified as for similar atactic samples. On the other hand, with both copolymers, the liquid crystalline behavior disappears to the advantage of crystalline phases independently on the backbone configuration. The results confirm that mesogenic interactions govern the structural behavior of such polymethacrylate polymers.