This paper provides a new approach to account for the relationship between diversification and innovation by integrating insights concerning strategic fit. We argue that the type of diversification strategy leads to greater innovation output when the appropriate technological search strategy is employed. Using a longitudinal study of the patenting activity of 258 manufacturing firms, we find that strategic fit is important for innovation output. More specifically, a related diversification strategy leads to greater innovation when firms use a narrow technological search strategy. In contrast, an unrelated diversification strategy leads to greater innovation when a broader technological search strategy is used. Implications for future research are discussed. Copyright © 2013 John Wiley & Sons, Ltd.