PurposeDespite the fundamental role of culture in an organisational setting, little is known of how organisational culture can be sometimes determined/influenced by professional culture, particularly in the global south. Using Nigeria as a research focus, this article uses critical discuss analysis to examine the link between professional and organisational culture.Design/methodology/approachThis study uses qualitative research approach to establish the significance of professional culture as a determinant of organisational culture among healthcare organisations.FindingsWe found that the medical profession in Nigeria is replete with professional duties and responsibilities, such as professional values and beliefs, professional rules and regulations, professional ethics, eagerness to fulfil the Hippocratic Oath, professional language, professional symbols, medicine codes of practice and societal expectations, all of which conflate to form medical professionals' values, beliefs, assumptions and the shared perceptions and practices upon which the medical professional culture is strongly built. This makes the medical professional culture stronger and more dominant than the healthcare organisational culture.Research limitations/implicationsThe extent to which the findings of this research can be generalised is constrained by the limited and selected sample of the research.Practical implicationsThe primacy of professional culture over organisational culture may have dysfunctional consequences for human resource management (HRM), as medical practitioners are obliged to stick to medical professional culture over human resources practices. Hence, human resources departments may struggle to cope with the behavioural issues that arise due to the dominant position taken by the medical practitioners. This is because the cultural system (professional culture), which is the configuration of beliefs, perceived values, code of ethics, practices and so forth. shared by medical doctors, subverts the operating system. Therefore, in the case of healthcare organisations, HRM should support and enhance the cultural system (the medical professional culture) by offering compatible operating strategies and practices.Originality/valueThis article provides valuable insights into the link between professional culture and organisational culture. It also enriches debates on organisational culture and professional culture. We, therefore, contend that a strong professional culture can overwhelm and eventually become an organisational culture.