This thesis studies the role of trust in the Catholic Reformation in seventeenth-century Genoa. It explores the way in which many reform-minded Catholics consciously tried to find an answer to the crisis of trust that dominated post-Reformation Europe by means of reforms and new initiatives. In particular, this dissertation examines how the effectiveness of these reforms and initiatives was impacted by practices of trust and distrust, as well as the reformers’ own perception of their strategies. Several features of the Catholic Reformation are analysed: the attempt to reform the secular clergy; new female religious initiatives; the effort to reform female cloistered life; and the establishment of new religious congregations. The trust approach used in this thesis constitutes an antidote to the current Italian paradigm in which the focus on power and discipline tends to obscure the plurality of the Italian Church in the seventeenth century. The concept moreover provides a key to explain several contradictions with which the current historiography confronts us such as the juxtaposition of instances of freedom and compulsion in the realm of female religiosity and the paradoxical coexistence of very ineffective and very successful attempts to reform.