The Old World braconine wasp genus Trigastrotheca Cameron is revised. The genus is recorded from the island of Madagascar for the first time based on two new species, T. christianhenrichi Quicke & Butcher, sp. nov. and T. formosa Quicke & Friedman, sp. nov.Trigastrotheca griffini Quicke, sp. nov. is described from Australia; T. aethiopica Quicke & Friedman, sp. nov. is described from Ethiopia; T. braeti Quicke & Butcher, sp. nov. is described from Congo; T. simba van Noort, sp. nov. is described from Tanzania; T. freidbergi Quicke & Friedman, sp. nov., T. carinata Ranjith, sp. nov., T. flava Ranjith, sp. nov. and T. similidentata Ranjith, sp. nov. are described from India; T. khaoyaiensis Quicke & Butcher, sp. nov., T. naniensis Quicke & Butcher, sp. nov., and T. sublobata Quicke & Butcher, sp. nov. are described from Thailand. Trigastrotheca tridentata is recorded from Thailand for the first time. A putative female of T. sureeratae is described for the first time. Acrocerilia tricolor Quicke & Ingram, 1993 is transferred into Trigastrotheca, as T. acroceropsisnom. nov. A key is provided for the identification of species.