Using data obtained from the Censuses of 1963 and 1971, the Socio-Economic Survey conducted from November 1969 to October 1970 and the Registrar General's Department, this paper analyses fertility trends in Sri Lanka during the period 1960–72 with special reference to the sub periods 1963–70 and 1963–71. The analysis indicates that changes in the proportion of women marrying was the most significant factor in the decline in the crude birth rate during 1963–70 and 1963–71. In the discussion on future prospects, attention is focused on the increase in contraceptive use from 1973 onwards together with other factors such as further postponement of marriage for women, a higher level of spinsterhood and emigration. The adverse effects on future fertility reduction of progressively larger female cohorts entering the main child-bearing years (20–34) are also discussed.