The ecclesiological reflection contemporary has highlighted the theme of ecclesial reform. The Second Vatican Council, Paul VI, John Paul II and Benedict XVI explained their need and Francis has sought to establish ecclesial processes according to the conciliar ecclesiological imperative of the continual reformation (Unitatis Redintegratio 6). Furthermore, if the Spirit is co-instituting of the Church, there are pneumatological elements involved in the notion of reform. To what extent did the Council and the recent magisterium link the Holy Spirit and the reform of the Church? Thus, the objective of this thesis is to analyze the historical-theological elements relevant to the notion of reform through the identification and investigation of pneumatological statements of recent magisterium for the consideration of ecclesial reform as a pneumatological event. The research is qualitative in terms of approach, exploratory in terms of objectives, and bibliographical and documentary research in terms of procedures. It is concluded that the notion of reform is eminently theological, rooted in the continuous return to sources, in the achievement of such a return in the ecclesial today and in the prospect of an eschatologically reformed Church as a pilgrim. The places of reform are the ecclesial subject (personal conversion), the ecclesial community (renewal of mentalities) and the evangelizing action (pastoral reform). From the perspective of the pneumatological statements of the recent magisterium, it is understood that the reform is a pneumatological event in four dimensions: the Spirit reforms the Church in communion, in truth, in charity and in mission. This is how by the power of the Gospel [the Spirit] makes the Church keep the freshness of youth. Uninterruptedly He renews it and leads it to perfect union with its Spouse (Lumen Gentium 4).