This dissertation studies the inclusion of the Islamist Movement of Unity and Reform/ Part}* of Justice and Development into the Moroccan political institutions. The aim is to trace and explain the Islamists’ choices in the institutional environment by considering the interactions of organisational, ideological, and institutional factors and their impact on the Islamists’ cost-benefit analysis. Tlie empirical sections of the dissertation are based on fieldwork, consisting of interviews with part}' and movement leaders, electoral candidates and party members, data on the party’’s congress deputies and electoral candidates, observations of the electoral campaign for the communal elections in 2003, party and movement documents, and newspapers. The first chapter develops the interpretative framework for the case study of this dissertation. Assuming that the inclusion of an Islamist movement involves challenges that are similar to those of other social movements when opting for institutional politics, it draws on literature on social movement integration into the political institutions, and on political parties in authoritarian and democratic regimes. It is discussed how institutional ©nstrainrs, ideological, and organisational factors might shape the Islamists choices and behaviour in the political institutions. The second chapter contextualises the broader issues raised in the first chapter in the Moroccan setting. It discusses the role and evolution of political institutions and political parties in Morocco and analyses the political liberalisation process in the 1990s in order to assess the margin oppositional actors have to promote their agenda. Additionally, it describes the evolution of the Moroccan Islamist movement up to inclusion and aims to account for the degree of active and passive support. Chapters III-V are the empirical analysis of the Moroccan case. The third chapter studies the development of party organisation over die last decade regarding the degree of institutionalisation, decision-making procedures, and membership. Tlie fourth chapter examines the relationship between the PJD and its founding organisation. It accounts for the autonomy of the party'’s choices in die institutional environment by looking at the formal and informal boundaries between the tw'o organisations and the part)’’s independent mobilisation resources. The fifth chapter studies the PJD’s course in the institutional environment since its first electoral success in 1997. It examines the evolution of the paity'’s hteractions with the palace, the party’s choices and internal debates regarding participation in national and local governance, and looks at processes of institutional socialisation of the PJD’sMPs and municipal councillors. The concluding chapter combines the findings of the case study with insights from the literature on the Egyptian and Jordanian case of inclusion in order to refine the analytical framework developed for the study of the Moroccan case. It is argued tliat Islamist ideolog}^ in its religious dimension had a negligible impact on the patty^’s choices, whereas the shape of party organisation, the party’s dependency on tlie support of the Islamist movement, and the nature of institutioral constraints in an authoritarian regime affected the part}’’s strategy considerably. Tlie findings of die dissertation make a case for studying Islamist parties within an analytical framework that is essentially identical with diose frameworks applied to the study of non-Islamist political parries in authoritarian regimes.