The fact that the permanent registration system of demographic events at the vital registration centre does not work well in Sub-Saharan Africa can be explained by the fact that most of the data on which researchers base their work come from population surveys (be they single passage or repeated passage surveys). But these data are often marred by non negligible declaration mistakes, and it is therefore necessary to resort to indirect mortality estimate.
But all approaches of adult mortality estimate (be it direct estimate or indirect estimate) are based on concepts and assumptions (be they implicit or explicit) which do not go beyond cultures. This is why these concepts and assumptions are exposed to major cultural disturbances which are not without consequences on the reliability of mortality estimates in Black Africa. This text draws attention on these risks and urges to take them into consideration in the collection and analysis of data on the African population in general, and more particularly on those relating to adult mortality. It is on these conditions that it is possible to hope for a better adult mortality estimate.