Cuproxena altimana is among the largest species in the genus, with a forewing length of nearly 9
mm. It is superficially most similar to C. speculana in size and in the presence of a nearly
uniformly white hindwing. It can be distinguished from the latter by the size of the semicircular patch, which extends from the costa to about the lower edge of the discal cell in C. altimana, but about 0.75 the distance from the costa to the hind margin in C. speculana.