Business-information systems (IS) alignment has become an important strategic imperative for organizations competing in the global economy. Recent research (Reich and Benbasat [56]) indicates that building a shared understanding between business and IS executives is one way of strengthening this alignment. This paper describes a study that examines the cognitive basis of shared understanding between business and IS executives. Using Personal Construct Theory (Kelly [36]), this study uses cognitive mapping techniques to explore the commonalities and individualities in the cognition between these executives. Eighty business and IS executives in six companies participated in this study. The results indicate that a higher level of cognitive commonality is positively related to a higher level of business-IS alignment. This is supported by findings that greater diversity in cognitive structure and cognitive content of business and IS executives coincide with a lower level of alignment. Implications for practitioners and researchers are discussed.