Drawing upon contingency theory, we analyze the antecedents and performance consequences of chief strategy officer (CSO) presence in top management teams (TMTs). We argue that strategic and structural complexity affects the decision to have a CSO in the TMT and its effect on firm performance. The results of a sample of S&P 500 firms over a five-year period reveal that diversification, acquisition activity, and TMT role interdependence are positively associated with CSO presence. However, we also find that the structural choice to have a CSO in the TMT does not significantly affect a firm's financial performance. This first systematic analysis of CSO presence informs research on CSOs and contributes to the emerging literature on TMT structure. Copyright © 2013 John Wiley & Sons, Ltd.