Cost analysis has undoubtedly become much more important today than ever before, especially because of the current economic depression. It should, however, have always been an essential part of programme and project management. We compared the cost of two malaria control interventions, DDT house spraying and permethrin-impregnated bed-nets for a population of 7712 in Florida Islands, Solomon Islands, and found that the 1989/90 costs of DDT spraying and the permethrin-impregnated bed-net operation annually cost (Solomon Island) SI$8.53 and SI$3.85 per capita, respectively. Even though these are relative, they presented the decision makers with an efficient choice of alternatives. Since cost-effective and cost-benefit analyses are much more complex and difficult in health, analysis of cost, itself an essential element of the above two analyses, would for practical purposes often be adequate evidence for decision makers. In April 1991, the Solomon Islands adopted a national policy of using insecticide-impregnated bed-nets as the main intervention in malaria control.