Photoinduced anisotropy (PA) is experimentally studied in three molecular glassy films synthesized in our Faculty and containing diphenylamine based azochromophores {4-((4-nitrophenyl)diazenyl)-N-(4-((4-nitrophenyl)diazenyl)phenyl)-N-(2-trityloxy)ethyl) benzeneamine (shortly K-D-24), 4-((2-chloro-4-tritylphenyl)diazenyl)-N-(4-((2-chloro-4-tritylphenyl)diazenyl)phenyl)-N-(2-(trityloxy)ethyl)benzenamine (shortly K-D-25), 4,4'-(2-(trityloxy)ethylazanediyl)bis(4,1-phenylene)bis(diazene-2,1-diyl)dibenzonitrile (shortly K-D-32) } and, for comparison, in an a-As2S3 film. Holographic method enabling simultaneous measurements of s- and p-polarized diffracted light powers was applied in both transmission and reflection modes. Holographic grating recording with the period of 2 μm was made by two equally strong 532 nm p- polarized laser beams with total light intensity of 0.81 W/cm2. The readout was made by 633 nm circularly polarized beam, and the s- and p-polarized components of diffracted light were separated by polarization beam splitter prism. PA was characterized by diffracted power difference (DPD), Ps – Pp , and by anisotropy contrast A = (ηs – ηp)/(ηs + ηp), ηs and ηp being the diffraction efficiencies for s- and p-polarized light. DPD exhibited markedly different kinetic behaviour in transmission and reflection modes. There was a negative minimum in transmission mode in all samples, and a growth with oscillations up to saturation in reflection mode. Small initial DPD maxima were specific to a-As2S3 film. The highest PA was found in K-D-24 film in transmission mode (A=-0.23) and in K-D-25 film in reflection mode (A=0.49). Holographic recording efficiency and PA do not correlate. In our opinion, PA in transmission mode of molecular glasses is due to the photoinduced volume processes including trans-cis photoisomerization , chromophore orientation and mechanical stress modulation. In the case of a-As2S3 film these photoinduced volume processes include photoinduced structural changes, D-centre orientation and, again, mechanical stress modulation. All these processes lead to a photoinduced birefringence. Surface relief grating recording and polarization-dependent reflection are responsible for diffractive anisotropy in reflection mode.