New technological developments make it possible to improve the quality of animal disease therapy, prophylaxis and diagnosis, and to improve animals' growth and fertility. The term 'quality' includes not only objective measurements, such as the fatness or leanness of meat, but also organoleptic factors such as flavour and others which are of increasing importance to consumers, such as animal welfare. Is new technology consistent with the improvement of quality? For example, beta-agonists and porcine somatotrophin reduce the fatness and increase the protein content of carcases, but there are also subtle positive relationships between fatness and eating quality. In contrast, bovine somatotrophin appears to have no effect on milk composition but there are indications that it may affect the perception of milk quality by some consumers. Improved vaccines can increase food quality by improving animal health and welfare and increasing the uniformity of the product; immunological techniques may also be used to improve meat quality. A gulf has developed between the benefits from new technology and consumer perceptions; indeed there is evidence of political resistance to some technological advances. Despite the stringent regulation of veterinary medicinal products in the United Kingdom and other countries, there is continued pressure for greater political control over their approval. The exchange of information between scientists, industry, the legal regulators and consumers must be improved so that advances in technology are acceptable to the majority and used to the advantage of all.