For 228 of 425 deaths (54%) occurring among 26 100 people of known age in the Malumfashi area of northern Nigeria, data were collected on symptoms present prior to death. Information was obtained on monthly registration visits, as part of demographic investigations, and data for the period November 1977-October 1978 have been analysed. Enumerators used a carefully prepared list of 25 symptoms to elicit information from relatives of the deceased. Pyrexia, diarrhoea and measles accounted for 77% of all deaths. Epidemiological determinants were responsible for all cases of meningococcal infections in the dry season and most cases of diarrhoea in the wet season. Most deaths attributed to measles occurred in the late dry season and early wet season. Epidemics of measles seemed to be localized at any one time in certain villages and the micro-epidemiology of this feature is considered. Malaria does not appear to be responsible for all deaths from pyrexia in the nought to four age group.