Nasonovia (Kakimia) stroyani n.sp. from the Pacific states of USA is described. The host plants are Tellima and Boykinia (Saxifragaceae). The species is closely related to N. (K.) cynosbati (Oestlund), but differs by having apterous males. Keys to apterous and alate viviparous females of the new species and various populations of N. (K.) cynosbati are given.