Aims: Milk is rich of nutrients that are necessary for the growth of various microorganisms. The aim of the present study was to evaluate the microbial quantity and quality of the raw cow’s milk sold through street trading in Meknes, Morocco, and to study the variation and seasonal relationship of microbial diversity during the four seasons of the year. Methodology and results: Raw cow’s milk samples were collected randomly between May 2015 and April 2016 from 3 street trading sale points, two popular neighborhoods (station 1 and station 2) and one popular market, and they were analyzed microbiologically. The results showed that the contamination rates of Total Plate Count (TPC), total coliforms, fecal coliforms, lactobacilli, lactococci and yeasts and molds were 8.8×108 CFU/mL, 8.9×105 CFU/mL, 2×103 CFU/mL, 4.6×108 CFU/mL, 7.5×108 CFU/mL and 4.1×103 CFU/mL, respectively. Moreover, Escherichia coli, Staphylococcus aureus, Clostridium perfringens and Listeria monocytogenes were detected in 66.67% (24/36), 75% (27/36), 36.1% (13/36) and 19.44% (7/36), respectively, while Salmonella was not detected in this study. Conclusion, significance and impact of study The highest microbiological count in raw milk samples was found in summer, while the lowest was detected in winter (p˂0.005). Therefore, the quality of milk marketed in Meknes region of Morocco is deteriorated due to the lack of good hygienic conditions of raw cow’s milk sold through street trading.