In 2003–2004, investigations of mycological contamination of stored and newly harvested vegetables were carried out. The aim of the study was to detect fungal species able to synthesize toxic metabolites, which are spread on vegetables under various conditions. For mycological investigations, samples of carrots, onions and cabbage were taken from storehouses with different storage periods and conditions. Penicillium expansum, P. nalgiovense, Mucor silvaticus and Penicillium verrucosum were more frequently detected on carrots, Penicillium expansum - on onions and Aspergillus niger, Botrytis cinerea, Mucor hiemalis, Penicillium funiculosum and Penicillium expansum - on cabbages. Storing conditions of vegetables influenced distribution of different fungal species. Primary screening using CYA and YES test-media showed that 46.7% of tested strains may be evaluated as toxin producers. The ability of fungi to produce mycotoxins depends on their growth substrata. According to Rf and fluorescence in the UV of compounds comparing with standards, such toxins as patulin, cytochalasin and penitrem were identified. The ability of Penicillium expansum Sv-168-1 growing on different foodstuff and especially potato to produce patulin was confirmed quantitatively.