Fungal contamination of food may be one of the more pervasive and seldom recognized cause of disease. Fungi produce mycotoxins that are versatile and potent causes of disease. Mycotoxins can cause acute and chronic illnesses, induce cancer, and damage vital organs. The purpose of this study was to isolate filamentous fungi from some foods and testing for mycotoxin production and finding the effects of some antifungal agents on to these isolates. Twenty-one fungal isolates were obtained from some of supermarket foods such as cheese, yogurt and olive. The majority of the isolates identified belong to the genera Penicillium sp. and Aspergillus sp. Taxonomical identification was based on the morphological characteristics of the fungi as observed under the microscope by using diagnostic literatures. These isolates were tested for mycotoxin production. Three of the fungal cultures were moderately toxigenic that including Penicillium sp. Effects of antifungal agents such as sodium nitrate, potassium sorbate, nisin, sodium propionate which can use food production prosess according to Turkish Food Codex were tested on fungi isolates. Potassium sorbate was most influential antifungal agent on our isolates.