Estimates of the economic returns from pig improvement in Great Britain are substantial. Genetic improvement in the national pig improvement scheme from 1970 to 1977 was estimated, using two control herds, to be 76 (s.e. 10) pence per pig per year. Stocks from breeding companies were of a similar merit from 1975 to 1980, so both groups were combined in the economic evaluation. Annual costs were estimated at €2 × 106 and annual benefits at approximately €100 × 106. The use of crossbreeding in commercial production was also estimated to contribute approximately €16 × 10 per year. These substantial figures are the best estimates available for the benefits, but some of the deficiencies are discussed.