Corporate social responsibility (CSR) has captured significant attention of managers and executives especially at multinational and multi-divisional firms. However, links between CSR's drivers (strategic planning, firm culture) and CSR have seen little or no empirical verification, particularly in South Asia. The present study aims to test two antecedents if they contribute in shaping firms' CSR. This study considers formal strategic planning and humanistic culture as drivers of CSR. Data were collected from CEOs of 800 randomly selected organizations in Pakistan, with 21.5% response rate. Results from hierarchical regression indicate that formal strategic planning and firm's humanistic culture, over and above the impact of formal strategic planning, are linked positively with CSR. Copyright © 2012 John Wiley & Sons, Ltd.