Introduction: Postpartum haemorrhage (PPH) is a leading cause of maternal morbidity and mortality worldwide, especially in resource-limited settings. Uterine atony accounts for most primary PPH cases. This study evaluates the effectiveness and safety of intrauterine balloon tamponade using a standard Foley’s catheter as an affordable intervention for atonic PPH unresponsive to medical management. Objective: To determine the haemostatic success rate, maternal outcomes, and complication profile of intrauterine Foley’s catheter tamponade after vaginal delivery. Methods: A prospective interventional study was conducted at a tertiary centre in Kolkata, India, from April 2022 to October 2023, including 140 women with atonic PPH unresponsive to uterotonics. After standard resuscitation, a 24-French Foley’s catheter was inserted and inflated with 60–120 mL sterile saline until bleeding stopped. Data on demographics, haemoglobin, blood loss, transfusion, surgical intervention, complications, and outcome were analysed. Results: Mean age was 24.75 ± 5 years; 59.28% were primiparous, 59.28% from lower socioeconomic class. Haemostasis was achieved in 89.28%, mostly within 5–10 minutes. Surgical intervention was needed in 10.72%. Sepsis occurred in 5.71%, acute kidney injury in 1.43%, and mortality in 0.71%. Conclusion: Intrauterine Foley’s catheter tamponade is a rapid, effective, low-cost option for managing atonic PPH refractory to medical therapy, suitable even in low-resource settings.