This paper includes an analysis of microbial contamination of Juglans regia L walnuts based on a bibliographic study of estimates made in the last 10 years by research workers from different countries. Existing studies show that nuts microbiota is quite diverse and is conditioned by many factors. If the conditions of fruit processing and storage are not respected, it leads to increasing the microbiological risk. This can affect the consumers health and can cause economic losses. The paper also presents an initial study of microbial contamination of walnuts grown in Moldova. The main objectives of the present research were to evaluate the mold, the total number of yeasts and other microorganisms of contamination in autochthonous Juglans regia L. walnuts, which were cultivated and stored at different stages of maturation. In the study (bibliographical and experimental), there are determined the factors which condition the microbiological risk, and are suggested ways to reduce microbial contamination of walnuts during storage.