At least 45 species belonging to the suborder Doridina are present in the 1990 Rumphius Biohistorical Expedition (RBE) collections, in addition to the 22 species of Chromodorididae and Hexabranchidae previously described by the author in 2001. In this paper, a total of 33 species belonging to 15 genera are identified and described from Ambon and nearby localities, comprising nearly 100 specimens. Three species are new to science but more material is needed, and eight species are recorded from Indonesian waters for the first time. As this is a paper identifying a major collection, brief descriptions are given for the species which are already well known, highlighting significant features and characters differentiating them from similar species, with figures where appropriate. A number of less well known species are described and figured in more detail. All species except Phyllidiopsis burni are illustrated with colour figures of living specimens.