This is a cross sectional descriptive study conducted in four geographical locations in Monrovia, Liberia, namely Bushrodrod Island, Sinkor, Central Monrovia, and Airfield respectively to examine the socio economic determinants of infant mortality amongst women who are reproductive in child bearing. A stratified random sampling was use with a sample size of 400. The main findings of this study are, access to health care, unskilled birth attendants, cultural and traditional practices, birth interval, displaced mothers, household condition and crowding, inadequate breast feeding and malnutrition have significant relationship with infant mortality in Monrovia, Liberia. According to the results of this study, infant mortality has a positive relationship with access to health care at 1% significant level, while birth interval has a negative relationship at 1% significant level. In the same vein, cultural and traditional practices has a positive relationship with infant mortality at 1% significant level. Following the same trend, unskilled birth attendants has a positive relationship with infant mortality at 5% significant level while displaced mothers has a negative relationship with infant mortality at 5% significant level. The study also found that household condition and crowding has a negative relationship with infant mortality at 10% significant level while inadequate breastfeeding and malnutrition also has a negative relationship with infant mortality at 10% significant level. Interestingly, the poverty variable turned out to be insignificant, although its coefficient entered with an expected positive sign, which may be due to regional differences as the results by geographic area indicates. These results provide useful clues for the design of future policies.