A series of liquid crystalline polymers possessing azobenzene chromophores were synthesized, and in each polymer the photorefractive effect of the isotropic phase was investigated. The photorefractive effect was evaluated by a four-wave mixing experiment. The diffraction efficiency of a side-chain liquid crystalline polymer possessing chiral moieties was measured and compared with that of a polymer possessing achiral chromophores. Chiral polymers exhibited unusual electric-field dependence on diffraction efficiency. The effects of liquid crystallinity and chiral substituents on photorefractivity are discussed.