To survey the overall fungal contamination and toxicological potential of isolated fungi, a mycological investigation of 56 samples of wheat bran was carried out during March-June 2004 in Slovakia. Despite of low values of water activity found in the samples reaching an average of 0.54, the individual samples were contaminated with fungi in a range from 1.82 x 10¹ - 3.42 x 10⁴ colonies forming units per gram of sample (CFU/g). A total number of 65 fungal species pertaining to 23 genera were recovered. The most dominant and diverse genus was Penicillium (20 spp.) followed by Aspergillus (10 spp.) and Cladosporium (3 spp.) with 100 percentages, 89 percentages and 72 percentages frequency, respectively. Isolates of potentially toxinogenic species recovered from the samples were found to produce various mycotoxins, namely citrinin (23 isolates), cyclopiazonic acid (43 isolates), griseofulvin (23 isolates), ochratoxin A (14 isolates), patulin (30 isolates), penitrem A (18 isolates) and sterigmatocystin (7 isolates). Furthermore, fumonisin B1 as well as moniliformin producing Fusarium strains, were recovered. It is evident that this type of cereal commodity is a significant source of toxicologically relevant species of which majority are true toxinogenic.