The combination of extracting, chromatographic and fluorescence densitometric steps permits to determine patulin in fruits and fruit products with great precision and sensitivity. The limit of detection is 10 microgram/kg; the recovery rates range from 86 to 92% with a variation coefficient lying between 5.6 and 13.6%. Interferences due to patulin-simulating substances are widely excluded. Patulin concentrations ranging from 0.3 to 42 mg/kg were found in the brown-rotten portions of apples. Juices domestically prepared from healthy fruits and fruits rid of rotten portions, respectively, contained no patulin. On the contrary, patulin concentrations ranging from 0.02 to 0.3 mg/l were observed in commercial apple juices. As to products with subsequent mould infection, patulin values up to 50 mg/l were found in apple juices, and up to 0.4 mg/kg in peach preserves. In a further 24 commercial fruit and vegetable juices, patulin was not detectable even not in cider, in cereals which had gone mouldy spontaneously, and in bread samples. The fruits and fruit products were analysed not only for patulin, but also for aflatoxin and ochratoxin; the latter two, however, were found in none of the samples examined. The possibilities of manufacturing patulin-free products are discussed.