A new genus and species of Masarinae (Vespidae), Priscomasaris namibiensis Gess, is described from Namibia. Cladistic analysis of the Masarinae shows that Priscomasaris belongs within the tribe Masarini, in which it is the most plesiomorphic member, and that it represents a new subtribe, here named Priscomasarina, sister to the subtribes Paragiina and Masarina combined. The justification by Carpenter (1997) for recognising subtribes, that is to have a group name for the Australian masarines, remains untouched. P. namibiensis visits flowers of Gisekia and Limeiim (Moluginaceae) and at pools lands on the water surface to drink.