After World War II, Náchod Castle was confiscated from the Schaumburg-Lippe princely family and became state property. On September 23, 1948, it was taken over by the National Cultural Commission. Jan Slezák became the first post-war castellan. The castle's furnishings were first catalogued in 1947 and then again in 1950. At that time, a number of items were discarded or taken elsewhere. Some of the castle's inventory was stolen in the early post-war years. Even so, a number of original items have been preserved at the castle to this day, supplemented by furnishings from so-called second-category castles (i.e., monuments that were not selected for public access). These included, for example, items from the castles of Horní Maršov and Bílé Poličany. At the end of the 1940s, the castle was reopened to visitors (tours of Náchod Castle were already taking place under the Schaumburg-Lippe family). In 1952, the tour route was modified, with the original wallpaper being removed and a number of items being stored in depositories. The interiors of the castle were intended to resemble the Piccolomini collections, but the interiors also featured portraits of members of the Schaumburg-Lippe family, which came from the castle in Ratibořice. Since 1958, the Náchod Castle complex has been a protected historical monument. Preparatory work on the complete restoration of the Náchod Castle began in the 1960s. The so-called model restoration began in the 1970s, when the castle was closed to the public. As part of the restoration, doors, windows, and fences were completely replaced, and new sgraffito facades were created. The castle was opened to visitors in 1977. At that time, the interiors were renovated again. All rooms were whitewashed, and the old floors were covered with modern parquet panels. The exhibition strictly presented the Piccolomini era and Baroque art. Much of the original castle furnishings ended up in
depositories. However, the complete restoration of the complex was not completed. It stopped at the entrance buildings –⁠⁠⁠ the administrative wing and the turion. Organizationally, the Náchod castle fell under the Regional Center for State Heritage Care and Nature Protection in Pardubice. After 1989, minor alterations were made to the castle interiors because items that were being returned to their original owners (e.g., to the chateaus in Rychnov nad Kněžnou and Doudleby nad Orlicí) were displayed there. At that time, the Schaumburg-Lippe family claimed restitution of the castles in Náchod and Ratibořice, but unsuccessfully. In the 1990s, the castle was administered by the State Heritage Institute in Pardubice, and since 2003 by the National Heritage Institute, regional office in Pardubice.