This article analyzes the geographic distribution and interrelationship of three measures of innovation commercialization across the 50 largest metropolitan areas in the United States and estimates a model of the factors explaining variations in the location of innovation commercialization. Innovation commercialization tends to be highly concentrated geographically, suggesting the presence of substantial external economies in these functions. Beyond these scale effects, however, the author finds that university science and engineering capacity and local patenting activity both help to account for intercity differences in the level of innovation commercialization activity.