Abstract Pergaphaga Gauld, a genus of ctenopelmatine Ichneumonidae endemic to Australia, is revised. The only previously described species, Pergaphaga nigra Gauld, is redescribed. Three additional species are newly described: Pergaphaga iangauldi Cammack & Wharton, sp. n. from New South Wales, ACT, and Victoria, P. leaski Wharton, sp. n. from Victoria, and P. xanthops Wharton, sp. n. from New South Wales and ACT. Keys to species and a phylogenetic analysis are presented. Morphological terms are linked to the Hymenoptera Anatomy Ontology.