This article investigates a case of successful union organizing in one automotive assembly plant in Romania. The authors argue that in order to explain why the union succeeds in defending workers’ rights there is a need to consider both structural and agency aspects that condition labor’s capacity to effectively defend their interests. The findings show that the union at the Romanian plant has made use of a diverse repertoire of protest activities in order to defend its worker constituency. The authors also discuss why as of late protests are less and less used by the union in response to the shifting economic and political environment in which the plant is embedded. They argue that a closer look at the strategy of the Romanian union and the path it has taken in the past decade provides a better understanding of the conditions for union success in an economic, legal, and political environment that has become increasingly hostile toward organized labor. In this sense, the article points to the more general situation unions in Central and Eastern Europe have found themselves in recent years.