This study uses annual time series data on under five mortality rate (U5MR) for Guinea from 1960 to 2020 to predict future trends of U5MR over the period 2021 to 2030. Residuals and forecast evaluation criteria indicate that the applied model is stable in forecasting U5MR. This study applies the Holt’s linear exponential smoothing model to predict U5MR. The optimal values for smoothing constants α and β are 0.9 and 0.3 respectively based on minimum MSE. The model projections revealed that annual U5MR will decline but remain high over the out of the sample period. Therefore, we encourage the government of Guinea to focus on improving the working conditions of healthcare workers and ensuring adequate medical supplies at all levels of healthcare by allocating more resources to the maternal and child (MNCH) program.