A novel homologous series RO-C6H4-COO-C6H4-N = CH-C5H4N of liquid crystalline Schiff base esters has been synthesized and studied with a view to correlating molecular structure to the liquid crystal properties on the basis of molecular rigidity and flexibility. All 12 members of series are either monotropic (C-1, C-3, C-5) or enantiotropic (C-2, C-4, C-6 to C-16) nematic with the absence of smectogenic character throughout the series. Transition temperatures and LC behavior of the series were determined using an optical polarizing microscope equipped with a heating stage. Transition curves (Cr-N or Cr-I and N-I or I-N) behave in the normal established manner as depicted in a phase diagram. An odd-even effect is exhibited by the N-I transition curve up to the C-8 homologue.