Dear Editor-in-Chief: Drugs used in animal farms can affect the public health because of their trace in edible animal tis-sues. Antibiotics are an integral part of treatment in many infectious diseases. They are widely used therapeutically, as growth promoters and to prevent infection in animals (1). After systemic or intrammamry administration of antibiotics in animal, antibiotic residues (ARs) in milk can be detected (2). In fact, consumers can inadvertently expose to these chemical compounds. ARs are important for three major reasons first, they can cause antibiotic resistance in microorganism (1). Second, antibiotics have side effects therefore, feeding of edible products containing ARs can cause similar complications. The possible complications can be from slight and transient changes in the body's natural flora to severe allergic reaction. Some antibiotics can cause allergies, even when used at very low doses (2). Third, the bactericidal and bacteriostatic activity of these compound, are interfering with the production process of some dairy products (3). Thus Maxi-mum Residue Limit (MRL) has been established in many countries. These MRLs are set at levels which are not likely to be exceeded if the veterinary drugs are used in accordance with approved label instructions (4). Iran has not established antibiotic MRLs level in milk. Previous studies have shown the high AR contamination in the milk sample in different cities of Iran. In the present study the contamination level of AR in raw cow milk sample in different part of Iran were assessed.