Economic efficiency in a breeding scheme is something dynamic. It is not possible to studythe situation, decide on the perfect solution and then implement it. Instead it is essential toconstruct something which is initially sound, based upon as wide a view of the industry’s requi-rement as it is possible to gain; this must then be allowed to respond continuously to new know-ledge and changing conditions.This review has examined some aspects of pig breeding schemeswhich affect their economic efficiency. These include the type of crossbreeding system, the selec-tion applied within the lines, the importance of starting up relatively quickly, of maintainingefficient production within the breeding herds and of structuring the scheme so that improvementsare passed down quickly to the commercial slaughter pigs.