The Acolastus ornatipennis species-group is revised. Two new species from Namibia are described, i.e. Acolastus borowieci sp. nov. and A. namibianus sp. nov. The new species are illustrated and a key to species is provided. Based on the records available, the A. ornatipennis species-group is endemic to Namibia. Including these two new species 10 species of Acolastus are currently known from Namibia.