This study uses annual time series data on under five mortality rate (U5MR) for the Gambia 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 model is stable in forecasting under five mortality rate. In this study the Holt’s linear exponential smoothing model was used to predict future trends of U5MR for the Gambia. The optimal values of smoothing constants α and β are 0.9 and 0.2 respectively based on minimum MSE. The results of the study indicated that annual U5MR will continue to drop over the out of sample period. Therefore, we encourage the Gambian government to address all the major challenges being faced by under five children across the country and ensure availability of medical supplies and staff particularly in the rural areas.