The impact of information systems and technology on business performance has increased noticeably during the last decade. This paper seeks to contribute to the literature on strategic IS management by pursuing three specific goals. First, it seeks to provide further insights into the performance implications of the alignment between business and IS strategies. Thus, in viewing alignment and its performance implications, this paper employs a theory-driven approach, which incorporates prior knowledge and is therefore able to contribute to the cumulative stream of research in this area. IS strategy is directly concerned with business applications, and there have been previous suggestions that it should be aligned with the business strategy. IS strategy attributes are mapped to IS strategy types in a similar manners The IS strategy best aligned with each business strategy is examined in terms of four IS strategy attributes. Three of these--operational support systems, market information systems, and strategic decision support systems--reflect the traditional classification of information systems into transaction processing systems, management information systems, and decision support systems, respectively.