The Spanish Constitution of 1978 states that the central Government has the total responsibility to legislate on prison issues even though the execution of that law can be carried out by the autonomous regional governments. So far, Catalonia is the only territory that has exercised this opportunity, and has regulated religious care in penal institutions through the Instruction 1/2005. This article analyses the wording of this administrative order to determine if it is coherent with the national legislation, with the prior agreements between the State and the Catholic Church, and also with other religious institutions. The minimum standard rules of religious care should be guaranteed in the Instruction,...