Regular rebasing is essential to ensure that gross domestic product (GDP) volume estimates remain relevant over the years by recording the importance of all economic activities as well as their relative prices. The base year of the actual GDP estimates of Sierra Leone is the year 2006. The new base will be the year 2018 and will provide an up-to-date and comprehensive estimate of Sierra Leone’s economic activity. At the request of the Statistics Sierra Leone (STATS SL), a technical assistance mission was conducted to provide guidance on the analyses of the source data and method used to compile the GDP data as well as to develop the Supply and Use Tables. The mission was conducted under the auspices of AFRITAC West 2, IMF.