A novel liquid crystalline (LC) homologous series of azoesters with a laterally substituted methoxy group RO-C6H4-COO-C6H3-(-OCH3)-NN-C6H4-COO-C4H9(n) has been synthesized and studied with a view to understanding the effect of molecular structure on thermotropic mesomorphism. The novel homologous series consists of thirteen homologues (C-1-C-18). The C-1-C-5 homologues are nonliquid crystals. The C-6 and C-7 homologues are only enantiotropically nematogenic and the rest of the mesomorphic homologues (C-8-C-18) are enantiotropically smectogenic and nematogenic. Transition temperatures and the textures of the mesophases were determined using an optical polarizing microscope (POM) equipped with a heating stage. The novel azoester homologues were characterised and confirmed using their analytical, spectral and thermometric data. Transition curves Cr-M/I, Sm-N and N-I behaved in normal manner without (Sm-N) and with (N-I) exhibition of odd-even effect respectively in a phase diagram. Thermal stabilities for smectic and nematic are 100.0 degrees C and 127.7 degrees C whose, mesomorphic phase length vary from 13.0 degrees C to 24.0 degrees C and 11.0 degrees C to 33.0 degrees C, respectively. The mesomorpism is compared with other known series.