BackgroundQuality improvement (QI) initiatives in healthcare are crucial for enhancing service quality and healthcare outcomes. The success of these initiatives depends on the active engagement of healthcare professionals, which can be influenced by several factors within the healthcare system. This systematic review synthesised the factors influencing healthcare professionals’ engagement in QI projects, focusing on identifying both barriers and facilitators.MethodsA mixed methods systematic review (MMSR) was conducted using the JBI methodology for MMSR. Databases such as MEDLINE, CINAHL, Scopus, and Embase were searched for studies that explored barriers and facilitators to QI engagement of health professionals in the clinical setting. Methodological quality was assessed using the Mixed Methods Appraisal Tool (MMAT). The extracted data were synthesised using the JBI convergent integrated approach to MMSR.ResultsEighteen studies (seven qualitative, nine quantitative, and two mixed-methods) published between 2007 and 2023 were included in the review. The analysis revealed barriers and facilitators to engagement in QI initiatives at different levels of the health system. At the QI program level, the engagement of health professionals to QI was influenced by the approach to QI, evidence underpinning the QI initiative, QI knowledge and training and access to QI specialists. At the health professional level, barriers and facilitators were related to their organisational role, motivation, perceptions about QI, and collaborations with individuals and groups. At the organisational level, factors related to culture and climate, leadership, available resources (including human resource and workload, infrastructure, and incentives) and institutional priorities influenced health professionals’ participation in QI.ConclusionThis review highlights the complex interplay of organisational, individual and QI program level factors that influence the engagement of healthcare professionals in QI. Overcoming these complex barriers and leveraging facilitators is crucial for enhancing participation in QI efforts. The findings underscore the need for a multi-level strategy that focuses on creating a conducive organisational culture, providing robust leadership, and ensuring adequate resources and training for healthcare professionals. Such strategies hold the potential to enhance the effectiveness and sustainability of QI initiatives in healthcare settings.