An investigation was carried out to determine the residues of azaperone in slaughter pigs and pig meat products. The butyrophenone tranquillizer azaperone is frequently administered to pigs by intramuscular injection in order to reduce mortality and loss of meat quality resulting from transportation from the farm to the slaughter house. In the pig, following administration of azaperone as recommended by the manufacturer (0.4 mg/kg i.m.) residue concentrations of about 0.05 μg/g azaperone, and 0.20 μg/g azaperol (the main biotransformation product in the pig) were found in the kidneys; the kidneys proving to be the sampling organs of choice. Pasteurization and other technological procedures did not influence residues measurably. Toxicological evaluation suggests that the residues found do notper seconstitute a danger to public health. None the less, the presence of any drug residue in meat or meat products is undesirable, and alternative, non‐pharmacological approaches to the problems arising from transportation prior to slaughter should be conside