The aim of the work is to show the pastoral activity of Diocese of Sosnowiec during the pastoral ministry of the first Bishop Adam Śmigielski SDB. The concept of pastoral care found its foundation in the teaching of the Second Vatican Council, John Paul II, and the pedagogy of Saint John Bosco, who became an inspiration for the Bishop as a Salesian, as well as in the models of patrons accepted for this local Church. The pastoral care in the diocese was a response to the social and religious problems of the faithful of the Zagłębie Dąbrowskie region. The work presents the development of the diocese with its structures and the first synod against the background of historical, religious and social conditions. The most important pastoral initiatives (care for the clergy, pastoral care of families, youth, working people, charity work), selected pastoral events and examples of Catholic associations, the function of sanctuaries and ecumenical activities were presented. The source of the research were archives of Diocese of Sosnowiec, texts of speeches by Bishop Śmigielski, theological and popular publications of the analysed period, as well as documents of the first Sosnowiec synod. The positions of secular researchers, especially historians and sociologists, were used to outline the socio-religious situation.