The Onchocerciasis Control Programme (OCP) in West Africa, launched in 1974, includes 11 participating countries and covers more than one million square kilometres. The aim of the OCP is to control blinding onchocerciasis (river blindness) which is caused by the savannah strain of Onchocerca volvulus transmitted by the Simulium damnosum complex. There is no effective macrofilaricide, so vector control to prevent the transmission of the parasite remains the method of choice, despite the availability of ivermectin, a drug which controls ocular morbidity. The potential value of vector control has been demonstrated by the original programme: 14 years activity has eliminated the disease as a public health problem in the areas included. This strategy requires adapted logistical support involving (i) widespread insecticide coverage (27,000 km of river are treated by the OCP during the rainy season), (ii) frequent (weekly) application of larvicide and (iii) prolonged intervention due to the life-span of the worm in the human reservoir, estimated to be approximately 14 years. We describe the vector control operations and their organisation 20 years after the initiation of the OCP. The OCP can be divided into 5 areas of logistic activity. The first covers activities involving insecticide and fuel management for the OCP as a whole: assessment of the requirements for the following year, ordering from insecticide and petrol suppliers, stocking fuel and insecticide at the depots covering the area. The second activity is the treatment of rivers with insecticide. This includes treating the ground with larvicide, the aerial operations run by an independent company supplying 12 helicopters on contract to the OCP, and use of satellite beacons for retransmitting of hydrological data. The third activity is monitoring the impact of larvicides on both the target (adult and larval S. damnosum) and on other fauna (fish, crustaceans and other insects). The fourth activity is field data collection and its processing. This involves a data transmission network to facilitate stock management insecticide application and entomological and hydrological surveillance using computer systems. The fifth activity is the coordination of vector control operations, technical and administrative staff and estimations of the funds available to the Vector Control Unit. The logistic aspects of other large-scale-insect-control programmes world-wide are considered, and the possibility of using the OCP as a model for such programmes (both public health and agricultural) is assessed.