High under-five mortality rate remains one of the public health challenges, especially in sub-Saharans Africa, accounting for more than half of all global cases. Sierra Leone was and still one of the countries with the highest under-five mortality rate. Using the latest 2019 SLDHS data, we investigated factors associated with under-five mortality in Sierra Leone. A total of 9771 mothers aged 15-49 years in the country were interviewed and included in the analysis. The dependent variable is child status (dead=1; alive=0). A total of 871 (9%) children died before their fifth birthday. Maternal age of 20-24 years (AOR=0.46; CI=0.33-0.64; P<0.001) up to 40-44 years (AOR=0.43; CI=0.27-0.7; P=0.001), currently breastfeeding (AOR=0.20; CI=0.17-0.24; P<0.001), maternal media exposure and usage of reading newspapers/magazines less than once a week (AOR=0.48; CI=0.28-0.85; P=0.011) were more likely to enhance child survivability through their fifth birthday. Also, the child sex being female (AOR=0.68; CI=0.59-0.79) was more likely to survive under-five mortality compared to their male counterpart. On the other hand, mothers who listened to radio at least once a week (AOR=1.31; CI=1.08-1.59; P=0.007) watched television less than once a week (AOR=1.48; CI=1.16-1.90), had two (AOR=3.4, CI=2.78-4.16; P<0.001) or three and above birth (AOR=8.11; CI=6.07-10.83; P<0.001) in five years, had multiple birth children (AOR=1.41; CI=1.08-1.86) and very small-sized child at birth (AOR= 1.95; CI=1.41-2.70) were more likely to lose their children below the age of five years.
The factors contributing to under-five mortality in Sierra Leone are critical to ensuring child survival and improving maternal health. Breastfeeding, maternal age, media exposure, child’s sex, multiple birth type, very small-sized child and the total number of births in five years were significant drivers of under-five mortality. The result affirms the need for attention to be focused on enhancing the survival rate of under-five children in Sierra Leone.