This paper examines the impact of geographic technological diversification on firm innovativeness. Our empirical study conducted on a panel of U.S. manufacturing companies shows that firms with geographic technological diversification are more innovative (as measured by both patents and citations) than firms without. Furthermore, we find that the positive relation between geographic technological diversification and firm innovation is driven by domestic technological diversification, while international technological diversification is negatively related to firm innovation. Our valuation tests further confirm the detrimental effect of international technological diversification on shareholder wealth.