This paper deals with the determinants of parliamentary turnover in 30 European countries. For the first time, the effects of macro-level factors of democratization, increased participation and increased contestation on turnover, were tested. The analysis has shown that the average turnover in European parliaments is around 35%, with a higher level of turnover in postcommunist countries, and a lower level of turnover in Scandinavian countries and the United Kingdom. A Bayesian beta regression analysis has revealed that the president’s power to dissolve the parliament, regular elections, bicameralism, party-system permissiveness and fractionalization, and postcommunist countries are associated with a high level of turnover. By contrast, federalism and personal vote are associated with a low level of turnover. The popular elections of the president, the prime minister’s power to dissolve the parliament, the length of female suffrage, intra-party defeat, gender quotas, and the temporal factor of the initial transition provide ambiguous results regarding their effect on the level of turnover in European parliaments.