The majority of food and ingredients is sensitive to the mold contamination in various stages of production, processing, transportation and storage. As well as climatic conditions and conditions during the process of production, transport and storage can cause mold growth and mycotoxin synthesis. Exposure to UV radiation negatively affects the growth of microorganisms. They can be inactivated especially by UVC radiation, wavelenght in the range 200 to 280 nm. This work explored the conditions of growth of molds Aspergillus ochraceus ZMPBF 318 and Penicillium expansum ZMPBF 566, pure and mixed cultures on solid substrate (malt agar) and on the natural substrate - apples after the irradiation with UV light of wavelength 254 nm for 180 seconds. Results are shown as log CFU / ml and percent of grown conidia. Stimulation and inhibition of mold growth is achieved in depenced of exposure to UV radiation.