Mordellidae collected on light during forays in 1974 - 75 and 1979 in South West Africa by Dr. H. Roer, Alexander Koenig Museum at Bonn, were examined. In this paper the results are reported; one of the six species dealt with is new to science. Diagnostic details of the genitalia of some of the other species are illustrated for the first time. Species collected: . Mordellistena (Mordellistena) schoutedeni Pic, . Mordellistena (Mordellistena) multistrigosa Ermisch, Mordellina (Mordellina) gracilis Schilsky, Mordellina (Mordellina) roeri n. sp., Mordellina (Pseudomordellistena) variabilis Pic, Neomordellistena variabilis (Neomordellistena) parvula Ermisch.