This article proposes an account of individual participation in social movements that combines structural and cultural factors. It aims to explain why certain activists continue to be involved in social movements while others withdraw. When activists remain embedded in social networks relevant for the protest issues and, above all, when they keep a symbolic linkage between their activism and their personal life-spheres, sustained participation is likely to occur. When these two factors become progressively separated from each other and the process of self-interaction by activists loses its strength, disengagement can be expected. The argument is illustrated with life-history interviews of activists who have kept their strong commitment to a major organization of the Swiss solidarity movement, and others that, in contrast, have abandoned their involvement. The findings support the argument that the interplay of the structural positions of actors and the symbolic meanings of mobilization has a strong impact on commitment to social movements and hence on sustained participation or disengagement. In particular, the interviews show the importance of a sense of coherence and of a holistic view of one's personal life for keeping commitment over time. This calls for a view of individual participation in social movements that draws from social phenomenology and symbolic interactionism in order to shed light on the symbolic (subjective) dimensions of participation,yet without neglecting the crucial role played by structural (objective) factors.