An increasing number of regionalist parties have participated in regional or national executive office. This article examines the specific conditions under which this party type increases its odds of successful cabinet entry – with a focus on ideological party change. Their programmatic profile is mapped before and after government entry by applying quantitative content analysis on coded electoral manifestos. The binary logistic regression analyses provide empirical evidence that regionalist parties that compromise on their territorial core business are more likely to enter (regional) government. Regionalist parties are also more likely to cross the threshold of (regional) governance when they operate in more decentralized countries and when they are a larger electoral factor in the regional political arena. Other relevant control variables, such as economic growth, national electoral score and party age, do not generate a significant effect on the odds of government participation.