Abstract Disaster response by philanthropy has faced numerous challenges flagged in the literature, including duplication of efforts, inefficiencies, waste, and inadequate goal achievements. However, there is little literature on how to organise philanthropic acts in the face of disasters. This paper assesses the influence of lean thinking in improving disaster response processes and sustainability. The paper further proposes a framework for applying lean thinking by philanthropic organisations. A mixed research methods strategy was employed with 212 staff surveys in Southern Africa. Twenty‐three in‐depth key informant interviews were also conducted. The results revealed that lean thinking succeeds with philanthropic organisations if a high level of management commitment, teamwork, and adaptability to change the organisation's setup exists. A framework is presented through Structural Equation Modelling (SEM), tailor‐made for philanthropic organisations in Southern Africa. External and internal determinants were found to equally contribute to lean thinking's success in reducing waste and increasing value. Despite being limited to developing economies, this paper extends prior research on the lean application and integrates lean thinking in a philanthropic setting. Findings drawn from diverse countries imply that results may be reasonably generalised.