Brood parasitism of Hooded Warblers (Setophaga citrina) by Brown-headed Cowbirds (Molothrus ater) has been well documented, but brood parasitism of this host by other bird species has not been recorded. Hooded Warblers are known to abandon nests with parasitic eggs early in the egg-laying phase, but are not known to remove parasitic eggs from their nests or to replace these foreign eggs with their own. In June 2017, a Hooded Warbler nest in northeastern Pennsylvania was observed to contain a cuckoo (Coccyzus sp.) egg. Within a span of 6 days, the cuckoo egg was gone and a third Hooded Warbler egg was observed in its place.