The article discusses the facade decorations of the tenement houses in Olsztyn's Old Town before and after the Second World War. This research comprises the original colour scheme of the tenement houses preserved from the destruction of war as well as the unique works of art in Olsztyn executed by local artists in the Polish People's Republic period. They include sgraffito, mosaics, and sculpted and colourful decorations of the tenement houses reconstructed after the Second World War. This article presents their history, authors, themes, techniques, and technologies. The documentation of this artwork sheds light on the art of that period and its artists, and shows a changing attitude toward historical monuments and the colour schemes during the postwar reconstruction in Polish towns at the time of the Polish People's Republic.