Objective: To propose a first set of consistent time-series of under-five mortality estimates for Sudan
and South Sudan from the 1950s up to today. Methods: Following the estimation procedure of the United
Nations Inter-agency Group for Child Mortality Estimation (IGME), a local weighted regression is fitted
on empirical under-five mortality estimates derived from the 1955-56, 1973, 1983, 1993, and 2008
censuses and sample surveys. Findings: Since the 1950s, despite two lengthy civil wars (1955-1972 and
1983-2005), the under-five mortality has declined in both Sudan and South Sudan. From a slow decline
between 1950 and the mid-1980s, the reduction accelerated thereafter, especially in South Sudan. In
2011, the under-five mortality reached 80.2 per 1,000 and 117.4 per 1,000, respectively in Sudan and
South Sudan. These levels are 38 and 47 per cent lower than in 1990. Conclusion: The proposed child
mortality estimates could be useful for policy-makers and organizations active in Sudan and South Sudan
as well as informative for the MDG-4 process in both countries.