Background: Primary postpartum haemorrhage (PPH) is a leading cause of maternal mortality in Ni-geria. Caesarean section (CS), though a life-saving alternative to vaginal delivery in several maternity units globally, is a risk factor for PPH. Its rate has increased globally with wide variability amongst various countries. Although tranexamic acid (TXA) is an affordable medication that has been widely investigated for the treatment of PPH, its role as prophylaxis against PPH during Caesarean section has not been well characterized in our environment. Methods: A randomized, double-blind, two-center study of 130 consenting pregnant women who were scheduled for either elective or emergency LSCS at the Institute of Maternal and Child Health, Lagos State University Teaching Hospital (LASUTH) and Federal Medical Center, Ebute-Metta (FMCEB) Lagos. Data was imported into Stata version 17 (StataCorp, USA) software for analysis. Results: The mean age of the participants was 30.8 ± 4.76 years. The prevalence of PPH among the placebo group was four times that of the Tranexamic acid group. (P-value < 0.0001). There was a sta-tistically significant lower estimated blood loss in the intervention compared to the placebo arm of the study (P-value < 0.0001) Conclusion: Prophylactic use of intravenous Tranexamic acid as an adjunct to uterotonic at caesarean section is efficacious in reducing blood loss and preventing post-partum haemorrhage.