The earthquake of October 3, 1943, is an important event for characterization of hazard in central Italy, but none of the earlier studies provide an exhaustive description of its effects. The context in which the earthquake occurred was very complex and many relevant records were not available for consultation when the studies were made. This study set out to improve our understanding of the earthquake and its effects by giving special care to the interpretative problems deriving from the peculiar historical and seismological context of the 1943 earthquake, with reference to the possible interactions between earthquake damage and war damage, and between the effects of the 1943 earthquake and those of other local earthquakes occurred between 1936 and 1951. The historical data set collected by earlier studies was critically revised and more data were sought in repositories that had not been previously considered. The number of localities for which a macrosesmic intensity can be assessed increased from 131 to 170. All intensity values were reassessed; from these we calculate a new macroseismic magnitude Mw 5.5 of the October 3, 1943, earthquake.