Ferrocene-doped poly(methyl methacrylate) (PMMA) thin films prepared from solution in chloroform and modified under photoexcitation have exhibited interesting photoswitching property monitored by photoconductivity measurements in air. The results on photoconductivity have been discussed on the basis of formation of photoinduced charge-transfer complexes of ferrocene with chloroform molecules confined in PMMA thin films, dissociation of the complexes, secondary thermal reaction and photodegradation of PMMA. Photodegradation of PMMA, was studied by FTIR spectroscopy. The modified ferrocene-doped PMMA films could be used as photoswitching elements.