This article investigates whether intraparty competition at the election stage – measured by the distribution of preference votes over candidates running under the same party label – is more intense in urban areas. Earlier research on preferential-list PR systems shows that urban voters are less inclined to cast preference votes. Yet we do not know how these differences at the individual voter level translate to the degree of intraparty competition at the aggregate list level. We hypothesize that urban areas provide a more open electoral market and lead to lower levels of vote concentration on party lists. We leverage a novel dataset on preference voting in three Belgian elections by aggregating 461,049 preference vote scores for candidates-in-cantons to a dataset of intraparty competition scores for 3,214 lists-in-cantons. The hierarchical models show that intra-party competition is impacted by the interactive effects of both the urban character of electoral competition and the presence of prominent office-holders. While rural contexts lead to greater vote concentration in presence of a larger number of office-holders, urban contexts often result in lower vote concentration. Our study provides novel insights into the contextual determinants of intraparty competition and personalization.