Does structural adjustment increase party system instability in Latin America? We employ the Latin American Presidential and Legislative Elections (LAPALE) database ( http://www.lapaledata.com ) and our own original data set for structural adjustment to assess the effects of structural adjustment and other economic, social, and political variables on legislative volatility in 18 Latin American countries during the period of 1982 to 2016. The results of our study indicate that structural adjustment results in higher levels of within-system electoral volatility and support a broad version of economic voting theory. Extra-system electoral volatility is driven primarily by institutional and demographic factors. Our findings also highlight the importance of disaggregating electoral volatility as within-system volatility and extra-system volatility appear to be largely driven by different factors, or in different ways by the same factors.