Purpose: The purpose of this paper is to introduce and test a portfolio view of a firm’s corporate social responsibility (CSR) activities. Drawing from stakeholder theory and the dynamic capabilities literature, the authors introduce CSR portfolio diversity and dynamism as key portfolio characteristics that have differential impacts across short- and long-term performance contexts. Design/methodology/approach: The study draws from the Kinder, Lydenberg and Domini database to examine CSR portfolio diversity and dynamism across seven dimensions of CSR activities. The authors test the direct and indirect relationships between CSR portfolio characteristics and both short- and long-term performance outcomes to assess the opportunities and challenges associated with managing a diverse and dynamic CSR portfolio. Findings: The findings suggest that a diverse portfolio of CSR activities positively impacts long-term performance; however, CSR portfolio diversity yields negative performance outcomes in the short-term. The authors also find that CSR portfolio dynamism moderates the relationship between CSR level and firm performance, such that a dynamic portfolio of CSR positively moderates the relationship between a firm’s CSR level and long-term performance; however, it negatively moderates the relationship between CSR level and short-term performance. Originality/value: This study integrates insights from the literature that examine the independent effects of individual CSR activities and the broader perspective that assesses the aggregated summation of CSR activities in relation to firm performance. By taking a portfolio perspective, the present study provides a unique integration of these two research streams to examine the performance implications of engaging in a diverse and dynamic range of CSR activities.