Malaria prevalence and status among other diseases were assessed in Suba District, Kenya, using data from past parasitological surveys and hospital records of clinically-diagnosed cases. A short prospective survey was also carried out to determine the methods people used for self protection against mosquito bites. Malaria was the leading cause of morbidity, constituting 42-48% of all illnesses clinically diagnosed at two health centres over a two-year period. Other common endemic diseases included infections of the upper respiratory and urinary tracts. The highest monthly number of malaria cases were recorded in July of each year. Malaria parasite rates in blood samples from people examined at 14 screening centres ranged from 24.4% to 99% over a distance of about 25 kilometres. The most popular method of self-protection against mosquitoes was mosquito nets followed by mosquito (pyrethrum-based) coils. Other methods included insecticidal sprays and smoke from plants traditionally associated with mosquito repellence.