Objectives Although a salient component of parliamentary delegation and accountability chains, the connection between individual campaigning and parliamentary behavior has not been measured systematically by empirical research. This study assesses the importance of campaign strategies and activities for constituency service. Methods We draw on an original data set combining the responses of 234 members of Parliament (MPs) participating at the 2010 Hungarian Candidate Study with their subsequent parliamentary questions. We content analyzed the questions and ran negative binomial regressions to evaluate if and how campaign activities influenced the MPs to introduce locally‐oriented questions. Results Our analyses show that a form of campaign socialization, the time devoted to meet local activists during campaigns, is a key predictor for the likelihood of introducing constituency questions, whereas campaign norms and messages matter less. Conclusions Ultimately, even though campaigns matter for constituency service, the MPs’ shadowing behavior, their socialization in local politics, and their partisan affiliation is likely to matter more.