It has been argued that targeting delivery of anthelmintics to school-children by taking advantage of the existing education infrastructure and administrative system can be one of the most cost-effective approaches in minimizing the intensity of infections with both schistosomiasis and major intestinal nematodes in many developing countries. The study was conducted in January 1997, shortly after the completion of the drug intervention programme. This paper provides an analysis of the costs of providing age-targeted treatment of schoolchildren for urinary schistosomiasis using praziquantel and for intestinal nematodes using albendazole as an integral part of the School Health Programme in Tanga Region, Tanzania. The analysis shows that the total financial cost of the intervention programme in 1996 prices was US$54 252.28 (exchange rate: TSH 573 = US$1). Of this amount, the cost of drugs constitutes 80.6%, while the delivery cost appears relatively low, representing just below 20%. Even when the opportunity cost of unpaid days of labour input is included, the cost of drugs still remains the highest cost component of the intervention (55.8%). In the current epidemiological and logistic setting of Tanzania, the financial cost per child treated using praziquantel, which involved prior screening at the school level, was US$0.79, while treatment using albendazole was as low as US$0.23, of which US$0.20 was drug purchase cost. It is concluded that the base cost of delivering a universal, standard, school-based health intervention such as albendazole can be as low as US$0.03 per child treated, but even a very slight increase in the complexity of delivery can have a very significant impact on the cost of intervention.