The orthodox church of St. Nicolas the Bishop at Kulaszne that is being dealt with in the present report was totally destroyed by fire in 1974. In view of a wide range of research problems associated with it the author considered it necessary to publish a set of materials concerning the above object. Within the first part of publication the archival, bibliographic and illustrative sources are presented then a full description of the object itself and the state of investigations is reported from which it follows that this church has been erected in 1883—1912 on a site occupied previously by another, earlier built church. The newly built church was erected with the use of carcass construction based on a stone sill. It was covered with gabled roofs provided with turrets and a lantern. The plan was divided into three clearly separated bodies with a porch and sanctuary enclosed at three sides. The ceiling was covered with figurai paintings dating from the time of erection. It was the most lately erected church within the space of the Osława Valley at the same time representing one of the last links in a chain of the so-called eastern-type orthodox churches on the territory of an ancient Lemki culture. As its prototype may, among others, be considered the orthodox church at Komańcza (1802—1836). That type of orthodox churches has developed in the first Quarter of the 19th century.