We study azobenzene-substituted diacetylene (PADA)/poly(methyl methacrylate) (PMMA) hybrid films that are pertinent to the problem of mirror symmetry breaking induced by circularly polarized UV light (CPUL). The morphology and packing structure of the resulting hybrid films were characterized by AFM and XRD. Striking CD signals for azobenzene chromophores and polydiacetylene chains were observed in the resulting polymerized PADA/PMMA hybrid films irradiated with left-or right-handed CPUL. Influence of the aggregation and orientation of azobenzene chromophores on the photoinduced chiroptical properties was analyzed in detail. Further, the effects of annealing treatment on photoinduced chirality of the hybrid films were studied. (C) 2010 Elsevier B.V. All rights reserved.