Sporadic deepwater sampling over recent decades has gradually revealed the fish fauna inhabiting these poorly explored habitats. Among the taxa emerging from this effort is Poecilopsetta (family Pleuronectidae), a little-known genus of flatfish collected in Australian waters since 1971. Several dozen lots now held in Australian natural history collections give us the first clear picture of the diversity and distribution of this genus in the region. Here we present the first comprehensive review of Poecilopsetta in Australian waters, recognising at least six species recorded to date. These deepwater specialists occupy depths of 200–500 m across tropical and temperate latitudes on both the western and eastern coasts of Australia. We discuss how these findings fit into the broader picture of deepwater fish assemblages, reflect on the mismatch between the timeline of specimen accumulation and the much slower rate of species description, describe our approach to resolving vague or outdated species descriptions, and highlight newer methods helping to advance understanding of this and other poorly known genera.