Radical left parties (RLP) have been significant actors in many Western European party systems since the expansion of mass democracy. In some cases, they have been very relevant forces in terms of popular support. Despite this fact, they have not received a great deal of attention in past decades from a comparative perspective. Through examination of the role of an important set of factors, this article provides, for the first time, a cross-national empirical account of the variation in voting for RLPs across Western Europe, based on individual-level data. It evaluates the effect of key socio-demographic and attitudinal individual-level variables on the RLP vote. The findings point to the continuing relevance of some social and political factors traditionally associated with votes for RLPs, and to the relevance of attitudinal variables.