Training health professionals is one of WHO's major strategies for improving health care in the developing world. The aim, to strengthen a country's own capacity rather than injecting expertise from outside, is in the best tradition of sustainable development. But how effective is this so called ''capacity building in human resources''? Since it accounted for $43m of WHO's budget in 1992-3 and is considered by WHO to be a major contribution to health in individual countries, it deserves detailed examination.