Malawi has one of the highest maternal mortality ratios in the world. Unsafe abortions are an important contributor to Malawi's maternal mortality and morbidity, where abortion is illegal except to save the woman's life. Postabortion care (PAC) aims to reduce adverse consequences of unsafe abortions, in part by treating incomplete abortions. Although global and national PAC policies recommend manual vacuum aspiration (MVA) for treatment of incomplete abortion, usage in Malawi is low and appears to be decreasing, with sharp curettage being used in preference. There is limited evidence regarding what influences rejection of recommended PAC innovations. Hence, drawing on Greenhalgh et al.'s (2004. Diffusion of innovations in service organizations: systematic review and recommendations. Milbank Quarterly 82: 581-629.) diffusion of healthcare innovation framework, this qualitative study aimed to investigate factors contributing to the limited and declining use of MVA in Malawi. Semi-structured interviews with 17 PAC providers in a central hospital and a district hospital indicate that a range of factors coalesce and influence PAC and MVA use in Malawi. Factors pertain to four main domains: the system (shortages of material and human resources ; lack of training, supervision and feedback), relationships (power dynamics; expected job roles), the health workers (attitudes towards abortion and PAC; prioritization of PAC) and the innovation (perceived risks and benefits of MVA use). Effective and sustainable PAC policy must adopt a broader people-centred health systems approach which considers all these factors, their interactions and the wider socio-cultural, legal and political context of abortion and PAC. The study showed the value of using Greenhalgh et al.'s (2004. Diffusion of innovations in service organizations: systematic review and recommendations. Milbank Quarterly 82: 581-629.) framework to consider the complex interaction of factors surrounding innovation use (or lack of), but provided more insights into rejections of innovations and, particularly, a low-and middle-income country perspective.