This thesis investigates the nature of women's participation in a political arena which they have entered in large numbers under varied political circumstances throughout the world - grass roots protest politics. A considerable amount of work has been done on women's political participation in working class radical politics in Europe and America. Very little research, however, has been undertaken on such participation by women in the developing countries despite the fact that it is in such countries that women tend to dominate in protest politics. This is especially the case in the popular urban social movements of Latin America. It has been argued that these movements emerge as a consequence of the socio-economic problems inherent to the urban sector of developing countries which create an antagonistic relationship between the State and the working classes and in many cases the conditions for radical political change. In addition, the study of the popular social movements is an under researched field of investigation in which there is no agreed definition about either their political significance or their role in the political process. In these circumstances, struggles by the working classes are not necessarily concentrated in or confined to the area of production but also to the areas of reproduction and collective consumption. It is in the latter that women have tended to dominate, as participants in and leaders of popular urban social movements. In Brazil, despite growing evidence of women's political role in the popular movements, studies undertaken in the last ten years on women's political participation have centred on political organisations such as trade unions and political parties. In these, however, women are underrepresented in numerical terms and their interests are not clearly articulated in the political programmes and objectives of these organisations. These studies focus on gender differences to account for the nature and extent of women's and men's participation in order to highlight the reasons for different levels of involvement. Explanations are given in many cases as to why women's political participation may differ from that of men, including the difficulties faced by women in these political organisations. Very few studies, however, have considered factors other than that of gender differences as influential to political commitment, political interest and political activity. Social and economic practices, the aims and objectives of political organisations and the characteristics of the political system itself all influence the nature and extent of women's and men's political participation. Studies of the popular urban social movements have either failed to mention the presence of women in them or if they have, have not attributed any political importance to this fact. Thus little research has been undertaken about women's participation in the popular movements and such research as has been carried out about the movements themselves has been both limited and contradictory in terms of its modes of investigation and analysis. The initial aim of my research was to investigate and provide some explanation for the marked presence of women in the popular urban social movements as opposed to other forms of political organisation. This aim arose from the sorts of questions raised in the literature when I started. However, many other questions arose in the course of my work. The evidence suggested that there might be a specific relationship between the popular movements and women's participation in them. If this was the case then the focus of studies of the popular movements would have to shift considerably to account for the role of women in this form of political organisation as one of the major components which contributes to the specificity of popular movements in the politicel process and in class struggle. In principle and in practice this would require a totally different type of political analysis. The aim of this study, therefore, is to present a different type of analysis. It focuses on the role of women in the organisation and formation of the popular urban social movements to contribute to a better understanding of both the movements themselves and the nature and extent of women's political participation in them. For this reason, considerable attention is paid to the way in which the political actors interpret what they do and how and why they do it. Traditional methods of research appropriate to the study of "formal" political structures which concentrate on an external view had to be abandoned in favour of a more fluid and participatory methodology.