Piper peltatifolium, a new species of Piperaceae from Hainan, China, is here described and illustrated. The new species is morphologically similar to P. hongkongense, but the former can be easily distinguished by the combination of characteristics: trophophyll blades peltate and subleathery with nonbranched hairs; leaves with longer sheaths; stamens usually only two; anthers ovoid and shorter than filaments; ovaries ellipsoid to ovoid; stigmas 3 or 4, or rarely 5; bracts suborbicular, sessile, and adnate to rachis; and drupes slightly hispidulous.