Reference materials are an important tool in ensuring the validity of the test results efficiently and economically. National Institute for Food Control has implemented several studies, characterization of microbiology chemistry for food and feeding stuffs certified reference materials (CRM) in order to support laboratories in control and maintaining test results quality. CRM for Escherichia coli (E. coli) in food is our study’s first interest, because E. coli indicates unfavorable hygienic conditions and fecal contamination in foods. Milk and dairy products are used for any stage of human life from infancy to elder. CRM for E. coli in milk-based products were characterized by using a network of competency laboratories leading to certified values in accordance with ISO 17034:2016 requirements. These certified reference materials produced are accredited conforming to ISO 17034:2016 by the America Association of Laboratories Association.