Antimicrobials are administered to animals by different routes for treatment and prevention of bacterial infection as well as to improve animal production. The miss use of antimicrobials in farm animals may lead to contamination of animal's byproducts (milk, meat and eggs). This may cause remarkable problems for both consumers and producers including hypersensitivity reaction, resistant development, economic losses in dairy industry and prohibits international trade. There is widespread concern about the presence of antimicrobials drugs in milk and meat. This study was conducted to determine antimicrobials residues in milk in Northern Jordan. 450 samples from the retail stores (Balady raw milk) and 150 samples from supermarkets (Ultra High-Temperature milk) were collected in January, March, and May 2006. Milk samples were screened by a microbiological inhibition test (Delvotest SP, DSM Food Specialties Dairy Ingredients) for the presence of antimicrobials drugs. Forty-eight out of 450 (10.66%) and 9 out of 150 (6%) were positive for antimicrobials residues in Balady and Ultra High-Temperature (UHT) milk samples, respectively. All positive samples of the screening test were exposed to 85°C for 5 minutes and Delvotest SP was repeated to exclude the presence of natural inhibitors. Four out of 57 Balady milk samples contained natural inhibitors. The presence of â-lactams and sulfonamides were confirmed initially by adding penicillinase and para-aminobenzoic acid, respectively to Delvotest SP positive milk sample. The positive milk samples were confirmed by high pressure liquid chromatography (HPLC) to quantify ampicillin, amoxicillin, penicillin G, cloxacillin, oxytetracycline, tetracycline, chlortetracycline and doxycycline. Forty-five out of 57 (78.95%) positive milk samples contained â-lactams residues (38 out of 48 and 7 out of 9, respectively for Balady and UHT milk samples). HPLC showed high mean level of amoxicillin, ampicillin, penicillin G and cloxacillin that exceed the maximum residual limits. On the other hand, 22 out of 57 (38.6%) positive milk sample contained tetracyclines residues (18 out of 48 and 4 out of 9, respectively for Balady and UHT milk samples). HPLC showed high mean level of tetracycline, chlortetracycline, oxytetracycline and doxycycline that exceed the maximum residual limits. 14 out of 57 milk samples contained both of b-lactam and tetracycline's residues. This study showed violation in producing antibiotic-free milk and therefore regulatory agencies should adapt a milk testing program to ensure high quality milk.