For-profit social enterprises are facing the dual challenges of fulfilling social purpose on the one hand and surviving business competition on the other. Being a sustainable for-profit social enterprise, the company must balance between economic, social and environmental aspects throughout their business operations. In order to achieve the desired end of sustainability, organization need to keep learning about the social needs and the business environment in order to develop sustainable business processes, and better fulfill their purpose as organizations formed to create social value. The study aims to fill the gaps in sustainability research literature about organizational learning in for-profit social enterprises by exploring how effective learning processes occur at individual, group and organizational level and how to facilitate these learning processes to improve sustainability. The study develops an analytical framework by combining the 4I framework for organizational learning process (Crossan et al., 1999) and an AKO (activities, knowledge source, outcomes) framework for understanding learning activities, knowledge sources and learning outcomes. Four for-profit social enterprises in both Denmark and Sweden are chosen as cases. Based on findings, three organizational learning mechanisms are identified on selected cases. Practical implications and insights are also generated for for-profit social enterprises to facilitate organizational learning for sustainability.