PurposeMicrofinance institutions (MFI) must adapt to rapidly changing market conditions, including stringent regulations and diverse customer demands, necessitating a high absorptive capacity. This research elucidates how organizational culture promotes knowledge sharing, thereby enhancing an organization’s ability to absorb and utilize new knowledge, with particular attention to the moderating role of MFI size.Design/methodology/approachData were collected from 450 randomly selected employees of MFIs in Pakistan. Hypotheses were tested using structural equation modeling in WarpPLS 8.0.FindingsThe findings show that knowledge sharing mediates the relationship between organizational culture and absorptive capacity. The impact is more pronounced in larger MFIs, while smaller MFIs exhibit greater agility in adapting to new knowledge.Practical implicationsMFIs, particularly in dynamic markets like Pakistan, should enhance their absorptive capacity by fostering an organizational culture that promotes knowledge sharing. While larger MFIs benefit from structured knowledge-sharing practices, they should address potential bureaucratic impediments to maintain agility.Social implicationsBy improving absorptive capacity, MFIs can better innovate and tailor their services to underserved communities, contributing to financial inclusion and poverty alleviation in Pakistan. This research provides insights for policymakers and practitioners on fostering sustainable development through strategic organizational practices in MFIs.Originality/valueThe findings offer a practical framework linking theoretical concepts from the resource-based and knowledge-based views to real-world applications, particularly in developing economies. It emphasizes the crucial role of organizational culture in enabling MFIs to adapt and thrive in challenging environments.