ABSTRACT Taxonomy of the Striated Grasswren Amytornis striatus complex has long been contentious and remains incompletely resolved. Its many populations are distributed widely but disjunctly and show only subtle distinction in morphology and plumage. Genetic data are meagre and have not been correlated with phenotype. We conducted a phenotypic analysis across its range and obtained mitochondrial DNA sequences from most populations. We recognise three species: south-eastern Striated Grasswren Amytornis striatus sensu stricto, Opalton Grasswren Amytornis rowleyi in central Queensland and Rufous Grasswren Amytornis whitei in the remainder of the range, with subspecies in the Pilbara and in the central and western deserts. In A. striatus as so circumscribed, we separate allopatric Murray Mallee and central New South Wales populations subspecifically. Isolated populations of Rufous Grasswren, from the North West Cape Peninsula, Western Australia and Eyre Peninsula, South Australia are also distinct. Awareness of such unanticipated diversity within the group has profound implications for conservation.