This article examines the conditions under which different kinds of parties resort to negative campaigning in three Western European countries: the Netherlands, Britain, and Germany in the period between 1980 and 2006. Data were collected for 27 parties, participating in 23 elections, yielding a total of 129 cases. The study uses a cross-nested multilevel model to estimate the effects of party characteristics as well as the electoral context in which these parties operate. It contributes to the state of the art on negative campaigning in two ways. First, being the first comparative and across-time study on negative campaigning, it compares negative campaigning across 23 elections, which is more than in any other study so far. It therefore contributes to the development of a more general theory on this type of campaign strategy. Second, it is the first study outside the American context to empirically estimate the effect of the electoral context on the use of negative campaigning. The results show that party characteristics are much more important than the electoral context in explaining when parties go negative.