In the early twentieth century in Portugal, nursing care was for the most part provided by religious women. Many doctors opposed this nursing care, such as the Republican Miguel Bombarda. However the religious nurses were absolutely necessary in order for health institutions to function, among these institutions, some of the Mercy hospitals stand out; however, not all of them had religious workers. Two examples were the Braga and Porto Mercy Hospitals. With this research I intend to understand the position of religious nursing detractors and identify the information that its defenders had. With this purpose, I used two existing sources at the Portugal National Library. Miguel Bombarda ́s work, A Enfermagem Religiosa, published in 1910, and the collection of testimonies collected by Rebelo Bastos in 1941, and published in 1974, under the title Para a História da Enfermagem Religiosa no Hospital da Santa Casa da Misericórdia de Lamego. When interpreting the data I used Catroga (1988), Silva (2008) and Moura (2010). The controversy between advocates of secular nursing and religious apologists nursing began in 1881, when the first nursing school was established in Coimbra. Defending secular nursing was the anticlerical and republican faction. This group understood that this work should be practiced by people with no connection to religious orders. Instead of professing a religious order, these people should have a degree in order to prepare them for the fulfilment of prescriptions and exclusive obedience to clinicians. Defending religious nursing were clerics; doctors, imbued with strong religiosity; and mercies managers. Those who worked with the religious praised their selflessness, tenderness and Christian spirit, in the nursing care. This controversy culminated in 1942 with the publication of Decree 32612. This edict forced the nurses both secular and religious, to possess a diploma in nursing. This was a requirement already demanded by Miguel Bombarda, three decades before. [ABSTRACT FROM AUTHOR]