A widely used demographic model of fertility, based on the proximate d
eterminants, is described. The model is fitted for three contrasting s
ub-Saharan African countries, using data from the 1980s round of Demog
raphic and Health surveys, to establish a baseline profile of fertilit
y for the period immediately before any widespread behavioural changes
in response to the spread of HIV can plausibly have taken place. Regi
onal variations in the relative significance of the different proximat
e determinants are noted, and considered in a discussion of the mechan
isms through which HIV could influence future fertility levels. It is
tentatively suggested that severe HIV epidemics are most likely to exe
rt a down ward pressure on fertility. More empirical data are required
to test this theory.