The crystal and molecular structures of diethyl 6-[4-(4′-nitrophenylazo)phenoxy]hexylmalonate (1) as a comonomer in the synthesis of liquid-crystalline polymers and its 2′-nitrophenyl isomer (2) have been determined by X-ray analysis. Both compounds crystallize in space group P1with two molecules per unit cell and the following lattice parameters.1:a= 7.995(2),b= 10.699(2),c= 15.021(4) Å,a= 95.04(2),β= 96.54(2),γ= 94.72(3)°.2:a= 8.912(2),b= 9.664(2),c= 16.064(4) Å, α = 98.68(2),β= 97.54(1),γ= 105.11(1)°. The structures were solved by direct methods and refined toR(wR) values of 0.082 (0.068) and 0.071 (0.076), respectively.