Three surveys were made by the Food and Drug Administration on fluid market milk to determine its content of antibiotics. In the 1st survey 3.2% of 94 samples contained penicillin. Cheese, butter, dried milk, and evaporated milk were also tested and contained no antibiotic activity. In the 2nd survey 474 samples of milk were tested and 11.6% contained penicillin. In the 3rd survey 1706 samples from the 48 states and the District of Columbia were examined and 5.9% showed penicillin in concentrations from 0.003 to 0.550 unit/ml. The problem of antibiotics in milk was discussed with a medical advisory panel and other interested parties in a meeting September 10, 1956. It was concluded that the presence of penicillin in milk might cause reactions in highly sensitized individuals. It was felt that other antibiotics, if present, did not pose a public health problem. The presence of penicillin in milk was believed to be due to improper use of mastitis preparations. The Food and Drug Administration is amending the antibiotic regulations to require a warning statement on the label of the container of mastitis preparations instructing the user to discard the milk for a 3-day period after the last treatment. An educational program pointing out the dangers of introducing penicillin in the milk supply and directing proper usage of mastitis preparations should be helpful in solving this problem. The use of antibiotics in feed to stimulate the growth of chicks, poults, and swine or for therapeutic treatment of disease in such animals is not believed to constitute a public health problem. Chlor-tetracycline and oxytetracycline are being used as a 10 ppm dip in the processing of poultry and a tolerance of 7 ppm has been established for any part of the raw bird. At this tolerance after the bird is cooked there is no antibiotic residue. Antibiotics are being used in the treatment of some plant diseases but here again there is believed to be no public health problem since the final product should contain no antibiotic residue.