Two homologous series of liquid crystalline azoesters consisting of a lateral hydroxyl substituent on the central benzene ring at 20 positions have been synthesized and thermally characterized. All the 24 members, of both series, exhibit high temperature nematic phases. All the compounds of both series are thermally stable and exhibit a wide mesomorphic range. The homologues have been characterized using Infra Red (IR), Nuclear Magnetic Resonance Spectroscopy (NMR), and Differential Scanning Calorimetry (DSC). Their mesomorphic properties and other characteristics are discussed.