In this paper we present the results of an investigation on the social action of the Catholic Church in the Archdiocese of Tarragona, in which the role that Catholic entities in the provision and social services compensations have in the scope of action of its territory. The initial hypothesis was that a broader coverage of the social action is the result of a major degree of decentralization and autonomy of the Catholic entities that are committed to this task. The design of the investigation combined qualitative techniques such as document analysis and in-depth interviews, as well as quantitative ones, based on the formulation of a survey for the entities. The questionnaire for the entities also included specific questions in order to develop a network analysis of the latter. The data was analyzed starting from conceptual approaches of theories such as the ecology of the organizations and the identification of future goals of the Catholic entities as organizations of the third sector. The data analysis leads to the conclusion that the religious entities make up an organizational pattern (isomorphism) in the form of a constellation network (environmental adaptability) from which its efficiency to unfold the coverage and the intensity of the social action derive.
