Background The health status of Rohingya refugees or Forcibly Displaced Myanmar Nationals (FDMNs), especially women and children, is a significant challenge for humanitarian workers in Bangladesh. Though the Government of Bangladesh, in partnership with other organizations, is offering health care services to FDMNs, a comprehensive understanding of the program implementation is required for continuation in the future. This study explores the challenges and potential solutions for effective implementation of maternal, newborn, and child health (MNCH) programs for FDMNs residing in camps of Cox's Bazar, Bangladesh. Methods We conducted a qualitative study conducted in Cox's Bazar district, Bangladesh, which involved 34 interviews (15 key informant interviews and 19 in-depth interviews) with relevant persons working in organizations responsible for MNCH services to FDMNs. We relied on both inductive and deductive coding and applied the Consolidated Framework for Implementation Research (CFIR) as a guide to our thematic analysis and presentation of qualitative data. Results Our study identified some key challenges hindering the effective implementation of MNCH service delivery for the FDMNs. High turnover and poor retention of staff, overlapping of service, weak referral mechanism, complex health information system, and lack of security of the front line health providers were some of the key challenges identified. Motivating the