In this paper, we draw from the resource-based theory to examine how information systems resources and capabilities impact firm performance. A basic premise of this paper is that variations in firm performance can be explained by how effective it is in using information technology to support and enhance its core competencies. In contrast to past studies that have implicitly assumed that information systems assets could have direct effects on firm performance, this study draws from the resource complementarity arguments and posits that it is the targeted use of information systems assets that is likely to be rent yielding. We develop the theoretical underpinnings of this premise and propose a model that interrelates IS resources, IS capabilities, IT support for core competencies, and firm performance.