Based on a demographic surveillance population from 39 villages in rural Burkina Faso, we describe mortality patterns in adults (15-59 years) and older people (> or = 60 years), and discuss seasonal trends in mortality. During the study period 1993-1998, 589 deaths in adults and 593 deaths in older people were recorded from an average adult and older people population of 13 550. The crude all-cause mortality rate per 1000 for adults was 7.3 (95 per cent confidence interval (CI) 6.7-7.8) and for older people 55.8 (95 percent CI 51.3-60.3). The probability of dying before age 60 after reaching age 15 was 34 percent for males and 32 percent for females. Malaria and diarrhoea, recorded through verbal autopsy, accounted for 21 percent of total deaths in adults and 22 per cent in older people. A seasonal trend in mortality for older people with a peak in February was identified. The study shows that malaria is an important cause of death in adulthood.