Background of the Study: Breast engorgement is a common and distressing condition experienced by postnatal mothers, particularly during the early stages of breastfeeding. It often leads to pain, discomfort, and breastfeeding challenges. Post-cesarean section mothers face additional barriers, such as physical discomfort and delayed breastfeeding initiation, which increase their risk of engorgement. Lukewarm water therapy, a simple, cost-effective intervention, is hypothesized to relieve breast engorgement by improving circulation and promoting milk flow. Aim: The study aims to evaluate the effectiveness of lukewarm water therapy in reducing breast engorgement among postnatal mothers aged 20–30 years who have undergone cesarean sections in a nursing home in New Delhi. Methods: A pre-experimental one-group pretest-posttest design was adopted. Thirty postnatal mothers experiencing breast engorgement were selected using purposive sampling. Participants received lukewarm water therapy twice daily for three consecutive days. Breast engorgement levels were measured using a standardized Breast Engorgement Scale before and after the intervention. Data were analyzed using descriptive and inferential statistics, with a paired t-test to compare pretest and posttest scores. Results: The results indicated a significant reduction in breast engorgement levels following the intervention (p < 0.05). Mothers reported relief from pain and discomfort, and there was a noticeable improvement in breastfeeding outcomes. Conclusion: Lukewarm water therapy is an effective, non-invasive method to manage breast engorgement among post-cesarean section mothers. It is recommended as a feasible intervention for improving maternal comfort and  promoting successful breastfeeding. Further studies with larger sample sizes and control groups are suggested to validate these findings.