This study uses annual time series data on under five mortality rate (U5MR) for Fiji Islands from 1960 to 2020 to predict future trends of U5MR over the out of sample period 2021 to 2030. Residuals and forecast evaluation criteria indicate that the applied model is stable in forecasting U5MR in Fiji Islands. The Holt’s linear exponential smoothing model was applied in this study to forecast future trends of U5MR. The optimal values for the smoothing constants α and β are 0.9 and 0.1 respectively based on minimum MSE. The double exponential smoothing model projections suggest that U5MR will increase over the out of sample period. Therefore, we encourage health authorities in Fiji to urgently respond to the likely future increase in under five mortality by allocating more resources to the maternal and child health (MNCH) program in order to reverse the projected undesirable future trends of U5MR. The government should quickly identify and address factors that significantly contribute to mortality among under five children.