In common with much of subSaharan Africa, falciparum malaria is a major cause of mortality and morbidity amongst the indigenous population of northeast Zaire1 although there are some mountainous areas in the east of the region that are relatively free from the parasite. There are a significant number of expatriate church workers (missionaries) in the area who work mainly in the health and development sector or directly with the local church in bible translation, evangelism, etc. The lifestyle of these workers, who tend to live close to the indigenous population, and their length of stay in a malarious region means that they are at high risk of contracting malaria.1 This population has been inadequately studied concerning its use of chemoprophylaxis and other measures necessary to reduce the risk of malaria. Many countries have published guidelines2-4 on the use of chemoprophylaxis for the prevention of malaria in travelers. This study was planned to investigate whether these guidelines were being followed by this group of missionaries. It also enabled the author to investigate who or what influences decisions regarding malaria prophylaxis amongst this population.