This catalogue presents all those works – paintings, sculpture, architecture, drawings, and prints – that no longer survive and for which there is some indication or record through the seventeenth century. Partial visual evidence for a very few is discussed with references to the related material in the Catalogue of Drawings and the Catalogue of Prints after Rosso’s Designs. The works are arranged according to their known, probable, or likely dates, and are numbered preceded by: L, followed by the date. Works that may have been done in Italy (or are last cited in Italy) but of which the date cannot be determined with any degree of likelihood are placed at the end of the section of lost Italian works. Undatable later works are designated as done in 1530-1540 and are situated in two groups among the French works. Five works are dated: 1530-1540? because the sources give no very clear evidence of when they may have been done, although a French date is probable. In a limited number of cases the number is followed by: Rosso? or: After Rosso? The prints are indicated as: After Rosso. The intent of this catalogue is to record those works that are no longer known in the hope that some may eventually be identified and to indicate the extent of Rosso’s artistic activity beyond that represented by the surviving works. Because of the different kinds of evidence for these lost works the arrangement of the contents of each entry varies. In general, however, the source or sources of our knowledge of the existence of the work is given first. In most cases this evidence gives also an indication of the date of the lost work. Its original location is considered as well as the duration of its survival. The literature on each work is considered, but mere citations of recent date are not indicated.