Chloramphenicol (Sigma) was added to the feeds of laying hens at prophylactic (20 and 40 mg/kg) and therapeutic (400 mg/kg) doses. Antibotic residues in eggs were determined by a disc assay methode Sarcinia lutea (ATCC 9341) was used as a test organism and brucella agar (Gibco) was used as a cultural medium. Broth cultur of Sarcinia lutea grown at 37°C for 16-18 hours, was seeded on brucella agar by disposable swab. Then, the discs absorbed chloramphenicol or egg extracts were set on the prepared plates. A total of 120 eggs were tested. Chloramphenicol residues in eggs of laying hens that have been given 40 mg/kg and 400 mg/kg doses were 10-115 ng/g and 35-75 ng/g respectively. It was shown that 6 mm in diameter could absorb an amount of 25 g homogenate of eggs.