This study uses annual time series data on under five mortality rate (U5MR) for Belgium from 1960 to 2020 to predict future trends of U5MR over the period 2021 to 2030. Residuals and forecast evaluation statistics indicate that the applied Holt’s linear model is stable in forecasting under five mortality rate in Belgium. The optimal values for the smoothing constants α and β are 0.9 and 0.1respectively based on minimum MSE. The Holt’s linear exponential smoothing model projections revealed that annual U5MR will continue to drop over the out of sample period. Therefore we implore health authorities in Belgium to design child health policies that are meant to keep under five mortality under control.