The Chestnut-breasted Cuckoo is dark grey above and bright chestnut below, with inconspicuous narrow white barring on the undertail. The eyering and feet are yellow. Younger birds are brownish below and grey-brown above, with a rufous rump. Within Australia it occurs within Cape York Peninsula, Qld, where it overlaps with the somewhat similar Fan-tailed Cuckoo C. flabelliformis, which is paler and with more prominent barring on the undertail. The species inhabits tropical and subtropical forests and mangroves, where it feeds on caterpillars and other insects, which are either gleaned from the canopy foliage or seized on the ground after being located from an observation perch. As with most cuckoos, the Chestnut-breasted Cuckoo lays its eggs in the nests of other birds and takes no part in incubation or chick-rearing duties. Targeted hosts include the Tropical Scrubwren.