Background Pakistan has a decent network of community-based workers including lady health workers (LHWs) and vaccinators. However, a major section of the population is not covered by LHWs/ vaccinators, labeled here as hard-to-reach (HTR) areas, where immunization coverage is also considerably low. This study explored the feasibility of engagement of traditional birth attendants (TBAs) to improve EPI vaccination coverage in HTR areas in rural Sindh, Pakistan. Methods This implementation research was conducted in two sub-districts of Sukkur (a district in Sindh Province). In an HTR selected intervention arm, TBAs were trained for vaccination and monetary incentives were provided to counsel and refer mothers for vaccination. While LHWs covered areas in the adjacent sub-district were provided with refresher training for vaccination only without any monetary incentive, and were considered as control arm. Considering the inherent differences in intervention and comparison group (HTR intervention area being worse regarding infrastructure and access), between groups and within group change in knowledge of TBA/LHWs and vaccination coverage was assessed before and after the intervention. Furthermore, focus group discussions were conducted with vaccinators, TBAs and LHWs and in-depth interviews with supervisors of vaccinators. Results TBAs and LHWs’ vaccine related knowledge increased significantly after training (pretest vs post test score: 10.5 to 15.4). The BCG coverage improved 74.1% (percentage change) in TBA arm. While completion of vaccination (ie, Penta-3 coverage) increased by 147% from baseline following the intervention. The TBAs, LHWs, vaccinators and their supervisors all welcomed the initiative and considered it as a feasible option. Conclusions Involvement of TBAs’ to form a referral system has potential to improve vaccine coverage and completion in HTR areas in Pakistan. The system is acceptable to the population and implementation is feasible due to availability of TBAs. However, in order to sustain the initiative minimal incentive need to be provided to TBAs to improve the vaccination coverage. Compared to establishing the infrastructure in HTR the intervention seems less costly however, it requires formal cost-effective or cost-benefit analysis.