This article seeks, firstly, to explore the influence of local level institutional and socioeconomic determinants on the Progress Party vote in Norway. Secondly, it examines whether the impact of these factors varies between municipal and parliamentary elections. Comparative subnational analysis of six elections (1995 2005) is conducted, treating 430-435 Norwegian municipalities as the units of analysis. Five variables related to electoral institutions, party competition, electoral behaviour and socioeconomic conditions are set against the Progress Party's vote share in a Tobit regression model. The results show that long-term institutional and party system variables have a permanent impact on the Progress Party's electoral fortunes, whereas the effect of short-term factors related to voting behaviour and socioeconomic conditions varies considerably according to the electoral context and election type. Furthermore, the political opportunity structure seems to be a stronger predictor of the Progress Party vote in the municipal elections than in the national ones.