Descriptions of eight new species of the genus Parancistrocerus Bequaert (Hymenoptera: Vespidae: Eumeninae), with a key to the Oriental species.

Eight new species, namely Parancistrocerus latitergus sp. nov. (China), P. lamnulus sp. nov. (China), P. laticlypeus sp. nov. (Thailand), P. prominens sp. nov. (Thailand), P. guangxiensis sp. nov. (China), P. discarinatus sp. nov. (Thailand), P. abyssicavus sp. nov. (Thailand), and P. similiandrocles sp. nov. (China) are described and illustrated. Parancistrocerus samarensis (von Schulthess, 1934) and P. incorruptus incorruptus Giordani Soika, 1972, are newly recorded from China and Thailand, respectively. An updated key to the Oriental species of the genus Parancistrocerus is also given.