<p>Does the uneven presence of organized branches of national parties influence the supply and success of local lists in local elections? To answer this question, we use data from six local elections in Portugal while controlling for the institutional, organizational, structural, and actor-oriented factors highlighted in the previous literature as drivers of the supply and success of local lists. Since the re-establishment of democratic rule in 1974, local elections in Portugal were under the monopoly of national parties, with local branches of national parties elected for all local offices. However, from the 2001 election onward, local lists were allowed by law to run for office. Given the uneven presence of national parties at the local level—varying from three in rural municipalities up to eight in Lisbon—we hypothesize that local lists are more likely to emerge and succeed in municipalities where the national parties are less present. The paper tests these hypotheses using data from six local elections in Portugal between 2001 and 2021. The results support the key hypotheses that local lists’ presence and success are associated with declining vote shares for national parties, particularly for those in the center of the ideological spectrum.</p>