In the year of the Monastery's dissolution, the monastic community of Santa Maria de Landim was made up of 17 canons and 5 lay brothers. Everything indicates that, despite the new dependencies with which the monastery was enlarged at the time of its 16th-century reconstruction, the size of the community was never very different from this order of magnitude.
The first prior of the Monastery of Landim, according to Friar Nicolau de Santa Maria in the Chronicle of the Order of the Canons Regular of the Patriarch St. Augustine, was D. Pedro Rodrigues, whom the chronicler describes as the son of Rodrigo Forjaz de Trastâmara and therefore the brother of Gonçalo Rodrigues da Palmeira, founder of the monastery. Although the name Pedro Rodrigues does not appear as one of Rodrigo Forjaz de Trastâmara's sons in any known genealogical compilation, and knowing that some of the facts narrated by the chronicler have no historical basis, the possibility cannot be ruled out that the founder, following the donation of the Couto da Palmeira, sought to consolidate his influence over the monastery through a blood brother. The priorate of D. Pedro Rodrigues was marked by the signing of the confirmation of the donation of that couto to the Monasterio de Nandim, & Ordini Sancti Augustini, by the sons of Gonçalo Rodrigues, in June 1177. He was succeeded by D. Pedro Garcia, nephew of the Archbishop of Braga D. Godinho — the prior who, after his death, was venerated as a saint by the people of Landim and the surrounding lands.
In the 13th century only two priors are known: D. Miguel, to whom King Sancho I, in 1210, delegated the mediation of the conflict that set him against D. Martinho Rodrigues, Bishop of Porto and grandson of Gonçalo Rodrigues da Palmeira, and D. Fernando Pires, Visitor General of the Order in 1228, appointed by the Cardinal of Santa Sabina, João de Abavila.
The name of D. Martinho Domingues, prior of the monastery between the first and second quarters of the 14th century, is mentioned by D. Rodrigo da Cunha in his Ecclesiastical History of the Archbishops of Braga, and of the saints and illustrious men who flourished in this archbishopric, as the one chosen by Archbishop D. Gonçalo Pereira, great-great-grandson of Gonçalo Rodrigues da Palmeira, to deliver the sermon at the Diocesan Council of Braga in 1328. Also from the fourteenth century is the priorate of D. Francisco Miguel, of whom it is only known that he moved from Landim to the Monastery of Santa Maria de Oliveira, where he was also invested as prior in 1356.
D. Martinho Gonçalves Taveira, whose priorate must have begun before 1423, was succeeded by his son D. Fernão Martins Taveira, chamberlain to the Duke of Bragança D. Afonso, the illegitimate son of King João I. The reasons that led to the resignation of these two priors are unknown, though in the case of D. Fernão Martins Taveira he may have been compelled by the Archbishop of Braga, D. Fernando da Guerra, for not professing the rule of the Canons Regular.
By at least 1446, D. Álvaro Afonso already presided over the destinies of the monastery, a priorate that would extend for more than three decades.
In the 15th century, Landim came to join the list of monastic institutions that became the object of commendam grants. D. Jorge da Costa, better known as the Cardinal of Alpedrinha, was most probably the monastery's first commendatory. In 1526, King João III appointed D. Miguel da Silva perpetual prior and commendatory of the Monastery of Landim and commendatory abbot of the Benedictine Monastery of S. Tirso. The granting of these commendams was likely no more than a conciliatory gesture towards Pope Clement VII, for the king had already ordered D. Miguel da Silva to cease his duties as Portugal's ambassador to the Holy See and to return to the kingdom at once, as a way of preventing the Pope from elevating the prelate to the dignity of cardinal, at the expense of a relative of his own. A driving force behind the introduction of Italianate architectural models in northern Portugal, it was during D. Miguel da Silva's tenure as Bishop of Viseu that the monastery's most profound remodelling began at Landim, as attested by the institution's Book of Deaths, which designates him as its commendatory and rebuilder. Yet the king's low regard for the prelate continued to show. To escape the threats and persecutions waged by King João III, D. Miguel da Silva decided to flee, in 1540, to Italy, hoping to find with Pope Paul III the welcome and protection he lacked in Portugal — which indeed came to pass, a year later, when he was invested as Cardinal in the Roman Curia. In the short interval between his flight and the issuing of the royal letter in which King João III stripped him of all favours, it was his nephew, D. António da Silva, abbot of the Monastery of Santo Tirso, who held the commendams. However, as a result of the negotiations meanwhile conducted between King João III and the Holy See, it was established that the new commendatory of Landim would be Cardinal Alexander Farnese, nephew of Pope Paul III.
The era of the triennial priors began in 1562, the year the Monastery of Landim joined the Congregation of the Canons Regular of St. Augustine, based in Santa Cruz de Coimbra. At the time of the Monastery's dissolution, in 1770, its prior was D. Agostinho de Nossa Senhora.