This article analyzes the implementation of gender mainstreaming at the local level in Sweden by investigating implementation gaps in the operations of two municipalities, Eskilstuna and Jönköping. The study draws on the literature on policy implementation, particularly the dimensions of comprehension, capacity, and will, as well as the feminist institutional literature on resistance. The data are based on a micro-study of the implementation of gender mainstreaming in two model municipalities, comprising interviews with key actors and a document study. The study shows that the key obstacles to the implementation of gender mainstreaming are complacency—that is, the perception that work on gender mainstreaming is satisfactory and that no extra attention to the matter is needed—and the congestion of perspectives—the fact that the gender equality perspective must compete with other relevant perspectives, a process in which gender equality is often the loser. Another obstacle is lack of political will. However, lack of political will, even in model municipalities, may be compensated for by solid systems of governance. The study contributes to research on implementation theory and feminist institutionalism by demonstrating the gendered barriers and obstacles to affecting change, even in best-case scenarios.