This article aimed to assess child immunization coverage in rural hard-to-reach hilly and low lying (haor) areas of Bangladesh. Status of fully immunized children was significantly lower in haor areas compared to hilly areas. Fully immunized children in both hilly and haor areas was significantly lower than concerned division as well as national level coverage. The results suggested that the traditional service delivery system is not sufficient for rural hard-to-reach areas of Bangladesh. The policy makers should come forward with innovative approaches for rural hard-to-reach areas of this country for improving immunization coverage.