The family is a classic Gondwana-distributed taxon, with extant members in South America, Madagascar, Australia, New Zealand, and New Guinea, and extinct taxa also in Antarctica.

Parastacidae belongs to the superfamily Parastacoidea, the monotypic taxon which contains all crayfish in the Southern Hemisphere.

Crayfish and lobsters together comprise the infraorder Astacidea, as shown in the simplified cladogram below:[2][3][4] Enoplometopidae Nephropidae Parastacidae Cambaroididae Astacidae Cambaridae Three genera are found in Chile, Virilastacus, Samastacus and Parastacus, the last of which also occurs disjunctly in southern Brazil and Uruguay.

The genera Astacopsis is endemic to Tasmania, while a further two are found on either side of the Bass Strait – Geocharax and Engaeus.

Three genera are endemic and have restricted distributions (Engaewa, Gramastacus and Tenuibranchiurus), while two are more widespread and contain more than one hundred species between them: Euastacus, around the Australian coast from Melbourne to Brisbane, and Cherax across Australia and New Guinea.