Abstract: The rate of turnover within parliaments remains an understudied area of research. The present paper contributes to filling this gap by presenting the first comparable macro-level data on legislative turnover in the 26 Swiss cantonal legislatures. In examining the strikingly different levels of turnover in sub-national Swiss parliaments between 1993 and 2011, the focus is on politico-institutional features. Multilevel models reveal that two hitherto neglected institutional variables are correlated with legislative turnover. In addition to the reduction of parliamentary size, we find the strength of a cantonal parliament to affect turnover rates on the Swiss sub-national level. Moreover, we show that proportional representation significantly promotes parliamentary elite circulation. Among the non-institutional covariates, we find that electoral volatility is also relevant in explaining legislative turnover rates.