This article develops the concept of gender frame for understanding major transformations in the collective action repertoires of social movements. Focusing on the United Mine Workers of America strike against the Pittston Coal Group, the article discusses the UMWA's traditional collective action repertoire and its innovation of nonviolent protest, widely employed during the strike. Interviews with major activists and UMWA staff and officers illustrate how the UMWA employed a gender frame of mining masculinities to initiate the new nonviolent strike action. (...) The article concludes by suggesting how collective action repertoires and framing are linked and encouraging future research on gender frames in social movements. (shrink)