The literature on far right parties emphasizes the importance of party organization for electoral persistence. Yet, a lot is still unknown about the organizational development of these parties. This article examines the microdynamics of organizational development and explores why some party organizations succeed and others fail. It focuses on the local rather than the national level and analyzes grassroots activities rather than party leadership, institutions, or members. To analyze organizational development, the article uses an original and unique data set of 3594 activities of the Greek Golden Dawn (GD) supplemented by interviews with the GD leadership and activists as well as with evidence from hundreds of newspaper reports. It uses this evidence to trace local party activism and to document variation in local organizational outcomes. To account for why some local party organizations succeed or fail, it suggests that, rather than solely following electoral logic, the organizational development of far right parties also relates to the way they respond to challenges from antifascist groups and state authorities.