This study examined the assimilation of business intelligence (BI) systems in firms. Based on the innovation assimilation concepts from information systems (IS) studies and considering the resource-based theory (RBT) as the theoretical underpinning, an initial research model was developed. The model was then validated with survey data that we collected from 153 managers and executives from Malaysia. The collected data were analyzed by partialleast-squares (PLS) methods. The results show that the assimilation stages (i.e., implementation and routinization) are not sequential (in other words, successful implementation does not ensure routinized use of BI systems); rather, implementation of BI systems enhances organizational knowledge culture, which in turn drives routinized use of BI systems. Data analyses also find that implementation of BI systems is dependent on three factors: quality of the BI system itself, quality of its users, and the governance of BI systems in firms. Our results offer new insights to theory and practice.