Argument still rages over whether vertical health programmes--attacking one or a few health problems--should still be set up in developing countries, or whether all their efforts should be devoted to establishing a horizontal multiproblem approach such as primary health care. This paper argues that the debate can be made rather more informed firstly by a consideration of the technologies available to improve health and the methods of delivery to which they are most suited; secondly by a consideration of their effectiveness and the organisational feasibility of different strategies of delivery, and finally, by investigation of the total costs and cost-effectiveness of different delivery systems. Particular attention is given to the contribution of economic analysis to elucidating these issues, and a variety of cost-effectiveness studies are reviewed to see what information is available on the way in which particular health programmes such as malaria control and immunisation activities can be organised in order to maximise their cost-effectiveness.