It is often argued that the growth of single-asset tourism places is fragile because it is vulnerable to economic fluctuations and is based on specialization and localization economies that lead to an ever stronger lock-in process of path-dependent urban economic development and, in the end, slow growth. In this paper, it is doubted whether a high urban tourism growth implies an ever stronger specialization and an ever stronger lock-in. This paper shows that the growth of tourism stimulates the growth of related and unrelated industries and generates a diversification of the economy, even though some other sectors are crowded out. Antalya (Turkey) is selected as a case-study area not only because its economy is dominated by tourism (it is a good example of a single-asset tourism city), but also because its economy shows a tendency to economic diversification at the sectoral level. This diversification tendency is shown by means of a shift-share analysis and Herfindahl indexes.