This study uses annual time series data of adolescent fertility rate for Sierra Leone from 1960 to 2020 to predict future trends of adolescent fertility rate over the period 2021 to 2030. The study utilizes Holt’s linear exponential smoothing model. The optimal values of smoothing constants α and β are 0.9 and 0.1 respectively based on minimum MSE. The results of the study indicate that annual adolescent fertility will continue to decline throughout the out of sample period. Therefore, we encourage authorities in Sierra Leone to relentlessly enforce laws that protect sexual and reproductive health rights of women and girls, promote girl child education, fund empowerment programs for youths and provide accessible and affordable adolescent health services across the whole country.