Pre-existing studies suggest that legislators in small districts tend to be more responsive to the electorate than those in large districts, as accountability is typically clearer in a smaller setting. However, it is not clear whether the relationship between district size and legislators’ constituency-oriented spending holds in other electoral settings (e.g., South Korea), where pork barrel benefits tend to be determined at the administrative unit, not the electoral district. The present study hypothesizes that as the number of legislators in an administrative unit increases, they are less likely to try to appeal to the voters. Additionally, this study examines the moderating effects of partisan homogeneity and legislators’ seniority. The results from the statistical analysis of data from Korean National Assembly members confirm our hypothesis: the number of legislators in an administrative unit turns out to be negatively associated with their vote-seeking behavior. Such a relationship tends to be strong in administrative units co-represented by multiple parties and weak among newly elected legislators.