Pachycondyla chinensis (Emery), introduced into North America more than 70 years ago, was considered an uncommon ant in Upstate South Carolina until 2003. Pachycondyla chinensis is now one of the most common ground-dwelling ants in forested and urban habitats in Upstate South Carolina; therefore, we surveyed P. chinensis-sting victims (i.e., from Anderson, Greenville, Oconee, and Pickens Cos., SC) to evaluate the public-health threat posed by the sting of this ant. Sixty nine percent of sting victims experienced local reactions including swelling less than 5 cm in diameter around the sting site, recurring pain, skin redness, and mild to severe urticaria (symptoms lasting 2 h-5 d). Fourteen percent reported minor reactions including no swelling, localized redness, minor pain sensation at the time of sting, and mild urticaria (<1 h). Fourteen percent reported significant large-local reactions including swelling more than 5 cm in diameter around the sting site, recurring pain, skin redness, and severe urticaria (3-14 d). A single individual suffered a systemic reaction (anaphylaxis) after being stung four times by P. chinensis, quickly developing hives over the entire body, chest pain, nausea, intense pain at sting sites, respiratory distress, and swelling of the tongue and face. The victim was taken to an emergency room where she was treated for anaphylaxis and later released. Continued range expansions, increased abundance, and increased reports of adverse reactions to their stings all indicate that P. chinensis is a public-health threat throughout its range in the USA.