This report presents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of residues of certain veterinary drugs in food and to recommend maximum levels for such residues in food. The first part considers the interpretation of data on inhibition of cholinesterase activity and recommendations arising from an informal meeting on harmonization with the Joint FAO/WHO Meeting on Pesticide Residues.A summary follows of the Committee's evaluations of toxicological and residue data on a variety of veterinary drugs: one anthelminthic agent (ivermectin), four antimicrobial agents (flumequine, lincomycin, oxytetracycline and tilmicosin) six insecticides (cyhalothrin, cypermethrin, a-cypermethrin, dicyclanil, permethrin and metrifonate (trichlorfon), and one production aid (melengestrol acetate). Annexed to the report are a summary of the Committee's recommendations on these drugs, including Acceptable Daily Intakes and Maximum Residue Limits and further information required.