The study reported here examined the relationship between executives' career experiences and their beliefs and understandings about the management of diversification. The study identified three broad sets of beliefs or orientations that executives hold about the management of diversification. In spite of a longstanding theoretical basis for hypothesizing that managerial demography will influence cognition, the study found no association between the top managers' career experiences that were considered in this study and their beliefs about the management of diversification. Based on this finding of a lack of relationships between demography and managerial beliefs, the paper offers some new theorizing on the relationship between career experiences and managers' beliefs about the management of diversification. It also suggests some implications for human resource practices, specifically the recruiting and development of top executives in large diversified firms.