Alignment between business strategy and IS strategy is relevant to most large organizations today. We build on the literature on alignment and strategic IS planning to study patterns of antecedents that explain planning decisions. When addressing misalignment risks: Are there systematic differences in the patterns of antecedents that explain decision-making across differing strategic orientations? This research question guides our investigation. By adopting an inductive learning methodology, a unique dataset – collected from a multi-business Fortune 10 organization – of proposed IS initiatives and the actual planning decisions is analyzed. We present insightful decision models and provide empirical support to suggest that strategic orientation is a key driver explaining the differences in decision-making during strategic IS planning.