This paper explores the existing knowledge retention strategies for professional nurses at Philadelphia hospital, in South Africa, located in one of the previously disadvantaged district municipalities in the country and it develops a strategy for retaining nurses. Design/Methodology/Approach: The study adopted a qualitative research approach and a case-study design. Semi-structured interviews were used to solicit in-depth understanding of the current knowledge retention practices. Out of the 90 professional nurses at Philadelphia hospital, 20 were purposively interviewed to a point of saturation. Data was analysed thematically. Findings: A knowledge retention strategy was developed. It calls for a knowledge retention policy; awareness training programmes; reward systems for effectively encouraging professional nurses to participate in knowledge retention practices; programmes for recovering lost knowledge and conducting knowledge audits. The strategy contributes to the existing body of knowledge-on-knowledge retention in the health care sector. The article is part of the findings from the authors master's dissertation. Conclusion: The loss of critical nursing knowledge remains a challenge in South Africa and to the rest of the globe, as highly skilled and experienced nurses migrate from place to place in search of greener pastures, hence this has affected patient care. Although the country has engaged in several efforts such as educating and training nurses, its knowledge retention strategies have not been prioritised in the country. Limitations: This paper focuses on knowledge retention practices in the nursing profession, which is only one part of the health sector in the former disadvantaged province. It is a qualitative study performed in one out of the nine provinces in South Africa. There is a dire need for a quantitative study, which will explore knowledge retention amongst nurses in the country and the health sector as a whole