Homologous 4-alkoxy-2-hydroxy-4'-formylazobenzenes (Alk = C3H7, C6H11, C8H17) were synthesized and were shown to produce monotropic nematic liquid crystalline phase. The products were characterized by electron absorption and H-1 and C-13 NMR spectra. The effect of lateral hydroxy group on their mesomorphic properties was analyzed.