Recent developments in supply chain management information systems have greatly increased the ability of firms to integrate processes, systems, and information with their supply chain partners. Despite the apparent benefits of web-enabled supply chain integration, its further study and application is hindered by the lack of an empirically supported model for classifying the varying levels of supply chain integration that are now possible using e-business technologies. This paper presents findings from a multiple case study used to explore web-enabled supply chain integration and identify potential questionnaire measures for further study. The questionnaire findings were corroborated by rich qualitative evidence from the five manufacturers studied, but highlighted several issues in measuring integration in web-enabled supply chains. In contrast to well-publicized examples such as Dell Computer, the cases studied exhibited a very modest level of supply chain integration, despite each having large investments in supply chain partnerships. This discrepancy highlights the need to measure supply chain integration using empirically-supported models such as the one described, rather than relying on managerial assumptions about how integrated a firm is with its supply chain partners.