This article explores the possible link between trade union organizing and industrial action. The focus is on Germany and the period between 2004 and 2015. During that period there was a significant shift in German strike activity from manufacturing to the service sector. Special attention will therefore be given to the United Services Union, ver.di, the second largest union in Germany. The article argues that major preconditions for organizing crystallize during industrial disputes. Strikes constitute decisive moments in which the diverging interests of employers and employees are directly experienced, and in which unions are called on to demonstrate their effectiveness as collective organizations. There is evidence that ‘organizing through conflict’ has the potential to support union building and that within such an approach industrial action can work as a catalyst. The conclusion is that successful strikes offer opportunities within a comprehensive organizing strategy without however being the magic bullet with which unions can easily close the representation gap.