A number of empirical studies have investigated the hypothesis that cross-border flows of goods (international trade) and capital (FDI) lead to international technology diffusion. The contribution of the present paper consists in examining an as yet neglected vehicle for technology diffusion: cross-border flows of people. We find that increasing the intensity of international travel, for the purpose of business and otherwise, by 1% increases the level of aggregate total factor productivity and GDP per worker by roughly 0.2%.