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 commonal-ities 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.