There are several factors that affect a firm's ability to successfully integrate internally and externally for organizational improvement. This study seeks to understand the relationship between a firm's strategy, its supply chain integration efforts, and firm performance. Leveraging the theoretical lens of structure–conduct–performance from the industrial organization economics literature, and utilizing both archival and survey data, we describe how firms may align their internal and external supply chain integration strategies with customers and suppliers. In doing so, these internal and external integration strategies affect the firm's ability to respond to customer demand, which then impacts operational and financial performance. Our work provides theoretical and empirical evidence of these relationships and thus extends prior strategic supply chain integration literature.