Milk, which is a basic component of the human diet since millennia worldwide, is rich in all kind of nutrients, thus comprises an excellent growth substrate for both beneficial and harmful microorganisms. As a result, milk contains numerous microorganisms deriving either from the animal itself or from the environment during the collection and storage of milk. These microbes can play a number of roles, such as facilitating dairy fermentations, promoting health, causing spoilage or even disease. For decades, the microbial ecology of dairy products has been based on the study of microbial isolates through conventional culture-dependent microbiological analysis. However, culture-independent approaches, and, most importantly, high throughput sequencing coupled with the omics-based techniques enable a thorough taxonomic fingerprinting of the dairy microbiota. This chapter provides a broad overview on the microbiota of raw cow's milk, as this has been described so far by both culture-dependent and -independent approaches.