This paper shows the employment structure of 16 European countries has been polarizing in recent years with the employment shares of managers, professionals and low-paid personal services workers increasing at the expense of the employment shares of middling manufacturing and routine office workers. To explain this job polarization, the paper develops and estimates a simple model to capture the effects of technology, globalization, institutions and product demand effects on the demand for different occupations. The results suggest that the routinization hypothesis of Autor, Levy and Murnane (2003) is the single most important factor behind the observed shifts in employment structure. We find some evidence for offshoring to explain job polarization although its impact is much smaller. We also find that shifts in product demand are acting to attenuate the polarizing impact of routinization and that differences or changes in wage-setting institutions play little role in explaining job polarization in Europe.