This is an introduction and analysis of the phenomenon of the new ecclesial movements that have sprung up in the Roman Catholic Church, mostly in the wake of the Second Vatican Council. This study, in examining three of them in some depth (Communion and Liberation, the Neo-Catechumenal Way and the Charismatic Renewal), concludes that "they are putting before the Church a model of Christian communion" which promises to change the Church of our time for the better.