Established firms need to go beyond their core business in order to survive rapid technological and market changes, which can be achieved through external corporate venturing (ECV) or the creation of new business external to the firm. This approach requires a firm to develop relevant capabilities. Existing research on capability development focus on learning-by-doing, an approach that exposes firm to the risk of failure and loss. Thus, this study argues that a less risky approach to ECV capability development is needed. One possible tool that can be used is strategic corporate social responsibility (CSR) that is designed according to a firm’s intention. In this context, CSR initiative can be used as a learning ground to develop a firm’s ECV capability without the typical pressure and constraints of a commercial project. The premise is explored by conducting a single case study of a startup competition held by an established ICT company in Indonesia that partners with three public universities. In this study, fifteen propositions on how strategic CSR can facilitate and support a firm’s development of ECV capability are developed, accompanied by potential challenges and solutions identified from both case study and literature study. By integrating ECV capability development and strategic CSR, a firm can achieve two objectives with one action while nurturing positive relationship with stakeholders.