Introduction and objectives:The healthcare system of India, being publicly funded relies on the numerous health programs run by the government. Maternal health is benefitted from many such programs. One such innovation by the National Health Mission, Tamil Nadu is the "mentoring" program, where obstetricians from the first referral units (FRU) mentor the service providers at the primary health care level. Our study aims to examine the efficacy of the program. Materials and methods: We conducted a prospective, mixed-methods, longitudinal study at Government Kamaraj Hospital, Chidambaram, Tamil Nadu. Two blocks of the taluk and their nine primary health centers (PHC) were included in the study. The two-mentor obstetricians gave virtual mentoring over WhatsApp groups and real-time mentoring by organizing camps twice a month and collecting the data. Results and discussion: A total of 1,054 antenatal women-kilometers per week were saved due to the reduction of travel from PHC to FRU. Reduction in the waiting time at the outpatient department (OPD) of FRU from 74 ± 31 minutes to 52 ± 19 minutes. Increase in the proportion of elective surgeries by 53%. Reduction in the rate of re-referrals by 5.8 times. The questionnaire-based satisfaction score showed 82% of the PHC team were extremely satisfied with the mentoring program. Conclusion: Mentoring of the primary health care providers by the obstetricians of the FRU is a novel and innovative concept by the National Health Mission, Tamil Nadu, and has helped bridge the gap between pregnant mothers and obstetricians in the resource-limited setting of the rural public sector.