This diploma thesis describes conservation and restoration work of the painting “The Landscape with The Hound of a Horse” by an unknown author. The painting is property of the Museum of Slavonia in Osijek since 1947. It comes from a confiscated castle Prandau-Normann in Valpovo. The Prandau-Normann family art collection is one of the most complete and best-preserved art collections of all Slavonia aristocracy. The main goal of conservation and restoration work on this painting was to prepare painting for the exhibition of the Prandau-Normann collection that is planned for early 2018. The theoretical part of this thesis is about the work of “Commission for the Protection and Preservation of Cultural Monuments” (KOMZA), whose members were given the task of inventorying, recording and organizing the safe storage for objects of cultural heritage from the Slavonia’s castles and confiscated objects. Main goal of this thesis is to present the importance of work that the Commission have done for the preservation of Croatian cultural heritage in the years after World War II. Practical part of the thesis focuses on conservation and restoration of the painting, with the greatest emphasis on the reintegration and patching the canvas. During a certain period, the painting suffered intense mechanical damage, most likely hit by a hammer or similar object. Every layer of the painting was damaged and the painting needed a full reconstruction. Original canvas from the edges of the painting was used for reconstructions of the canvas layer. It was decided that the painting will be lining completely on the new canvas. The reason for that was to secure the enormous number of patches and the stability of the painting. At last, the painting was retouched and then varnished. Upon completion of the works, the image will be returned to the owner with complete conservation and restoration documentation.