On December 29, a devastating Mw6. 4 earthquake occurred near the town of Petrinja in central Croatia, preceded by a foreshock the day before. The epicentre of the mainshock was located just 6 km southwest of Petrinja. In addition to extensive damage to buildings in Petrinja, the earthquake also caused damage to buildings in the nearby towns of Glina and Sisak, as well as throughout Sisak-Moslavina County. The basic building typology in the affected area consists mainly of unreinforced masonry buildings and, to a lesser extent, of confined masonry buildings, while the newer buildings are made of reinforced concrete. Depending on the period of construction, unreinforced masonry buildings were more susceptible to damage and to the occurrence of in-plane and out-of-plane failure mechanisms due to their relatively high seismic vulnerability. This paper summarises the most typical damage to the masonry buildings observed in the field and highlights the relevant failure mechanisms.