This paper uses a method for estimating age-specific event rates for adults (15–49 years) in Malawi between 1977 and 1998. This method, which is based on the development of unstable populations, is similar to the “variable-r” methods. Data from Malawi demonstrate mortality reduction nearly for all age groups between 1977 and 1987 for males whereas for females the reduction was observed for age groups 15–19 and 40–44. Contrary to this finding, the 1987–1998 intercensal period shows that mortality increased at a higher rate in the ages 20 and above for males than females. However, the increase for the females is much higher in the 1987–1998 intercensal period than in the 1977–1987 intercensal period. These findings may be related to the onset and effect of the AIDS epidemic. Implications for future research are discussed.