We investigate trends and cross-national variation in the impact of class, religious, and gender cleavages on voting behavior in six advanced capitalist democracies in the postwar period. Earlier research on cleavage voting has been criticized for utilizing outdated “two-class” models of class structure, simplistic left/right party distinctions, flawed statistical approaches, and incompatible and/or limited of cross-national empirical evidence. We take such criticisms seriously and seek to overcome them. Using multinomial logistic regression models, we analyze data from a new dataset, the International Social Cleavages and Politics (ISCP) file, which contains comparable, over-time cross-national data from 112 nationally representative election surveys of voters in six Western democracies in the period 1964–1998. The six countries examined in the paper (Australia, Austria, Germany, Great Britain, the Netherlands, and the United States) are unique because of the existence of time series data available for all three cleavages. Our analyses examine the changing magnitude of the class, religion, and gender cleavages for up to five distinct party families for each country. Unskilled workers have become less distinctive in their partisan alignments over time, but other classes have experienced offsetting changes, yielding little evidence of a universal decline in the class cleavage. Further analyses suggest an important degree of stability in the aggregated effects of all social cleavages, while also revealing significant cross-national differences and trends in the magnitude of specific cleavages. These results refine debates concerning the possible decline of social cleavages; implications for research are discussed in conclusion.