In this research is provided a comparative analysis of workers’ mobilisation through a qualitative interpretation of processes, dynamics and effects of collective action in two care multinationals in Córdoba, Argentina, during 1996/1997. What drives workers to periodically contest their surrounding reality and how do they structure their protests? The thesis is based on the view that conflict is inevitable, mobilisation representing one possible form of it, due to the position workers have in the employment relation and for the constant existence of a gap between social needs and commodities produced within capitalist systems. Mobilisation is based on these theoretical objective conditions but subject do not immediately realise this and in the same terms, the process of collective protest implying in itself a deeper consciousness among workers of the meaning of their action. When subjects contest the inevitability of the social system surrounding them remains unpredictable, but the thesis has identified some factors whose absence or presence profoundly influences the chances for collective action to start and be maintained. At the same time the emphasis on the factors that are obstacles to mobilisation allows us to understand the concept of solidarity and its importance within the same process of mobilisation. Contrary to theoretical perspectives that intend collective action as based on individuals’ sense of injustice, this thesis emphasises the need for a reconceptualisation of solidarity within a theory of mobilisation. More generally the thesis calls for a re-evaluation of collective action as a process intrinsically collective whose nature disappears within a social context that constantly tends to individualise and divide. The case of Argentina and the historical perspective within which the mobilisations analysed are inserted, invite us to reconsider the role of traditional trade unions as organisers of protest and the relations between isolated workers’ struggles and more generalised social protests.