ENIn the late Middle Ages and the Early Modern period, the development of the parishes of the Samogitian Diocese was affected by demographic factors, the prevailing religious relationships, and the formation of the land use and economic conditions. In the second half of the 16th century, most of the life areas in the Grand Duchy of - Lithuania flourished. However, the Catholic Church, including the development of its parishes, experienced a crisis around 1555 to 1593 due to the increasing influence of Reformation: it was reflected in a number of spheres of parish life and in the reduction of the parish network. Instead of 45 Catholic churches recorded in 1555, merely 27 were left in the period of 1593-1596. Historians doubt whether all of them were functioning. They do not exclude a possibility that there could have been even less of them in the late 70s of the 16th century. Therefore, historiography accepts that the “bottom“ of the above mentioned crisis of the church network development coincided approximately with its last decade. A unique witness to the parish situation of that period was a rather extensively analysed visitation of the churches in the south-eastern and partly the central part of the Samogitian diocese carried out in 1579 by auditor Tarquinius Peculus of apostolic nuncio G.A.Caligari. On the basis of the document, the research analysed the social organisation of parish holdings with the aim of identifying the social structure and functions of them as economic units and of naming the major characteristics of the development of a social-economic character.that took place in the parish holdings of the Samogitian Diocese. As proved by the findings, one could identify the traits of a schema typical of the staff organisation in the manors in the parish holdings of the Samogitian Diocese. At a critical moment of the crisis of the Catholic Church, economic activities in parishes sought to adapt to the economic-social conditions of the time. The efforts were felt both in poor parishes with the income of merely 2 to 6 threescores of groshes and in richer ones with the income of 8 to 100 threescores of groshes. Even in parishes with small numbers of serfs, innovations that were to ensure larger income, such as corvee and feudal land rent, were introduced. Richer parishes with the annual income of 12 threescores of groshes and more had from one to several administrative staff members. The presence of even small groups of hired farmhands in most of the parish holdings suggested that economic activities took place not only on the parish lands, but also in the farmstead of the property manager. The character of the social structure recorded in our research suggests the existence of manor economies in some of the parish holdings or at least attempts to organise and maintain them. However, the conducted research should be considered as primary, while deeper evaluation of the social and economic situation calls for more extensive studies of the economic structure of the parish holdings. Therefore, the obtained findings should not be so far related to the process of economic activities in the second half of the 16th century.