In the current study, the physicochemical analysis of 48 different corn and corn-based products samples collected from Assiut Governorate revealed that among the corn sources, white corn had the highest concentrations of total carbohydrates, protein, sodium , magnesium, chloride, phosphate and sulphate. As for, corn-based products, flamenco recorded the highest content of moisture, lipids, proteins, nitrate, phosphate and sulphate. Mycological analysis of these samples resulted 37 fungal species in addition to one varity belonging to nine fungal genera. Aspergillus flavus and A. parasiticus were consistently the most common species in all samples. It was concluded that the  physicochemical properties of collected samples displayed the main role governing the biodiversity and abundance of isolated fungi. Using TLC technique, results indicuted that from 71 Aspergillus isolates tested for their potential ability to produce aflatoxins B1 ,B2 ,G1 and G2. Thirty-four fungal isolates could produce these toxins with different abilities. The study revealed that 50% of the tested isolates related to each of A. flavus and A. parasiticus in addition to 20% of those releated to A. flavus var. columnaris could produced aflatoxins with different abilities. It was noticed that all collected corn and corn-based products samples were differently contaminated with aflatoxins. The HPLC technique was used for confirmation and quantification of aflatoxins levels in the extracts of the most aflatoxins-producing potential fungal isolates of A. flavus (AFC3) and A. parasiticus (APP56). In addition, aflatoxins level was estimated in  the two samples from which the two previous fungal isolates were recovered. A. flavus  (AFC3) produced aflatoxins B1 and G2 with a total concentration (34.832 ng/g),while A. parasiticus isolate (APP56) produced B1 , B2 and G2 with a total concentration (21.82 ng/g). As for cornflakes sample from which AFC3 was isolated, it contained B1 (9.206 ng/g) and G2 (1.531 ng/g), whereas popcorn sample from which APP56 was isolated contained B1 (2.942 ng/g) and G2 (17.433 ng/g). Presence of aflatoxigenic aspergilli in corn and corn-based products gives the probability of aflatoxins formation in these samples. In addition,the natural occurrence of aflatoxins in cornflakes and popcorn with a level which exceeds a lawable limit of these toxins in many countries all over the world represents hazard and  threatens the public health.