The adult Oriental Cockroach is a shiny black or dark-brown color. The younger members are darker and not shiny like the adults. The male of Periplaneta americana is smaller than the female. Males are about 2.6 centimeters in length, while females tend to be from 2.6 to 3.25 centimeters in length. The average male weighs approximately .45 grams while the female weighs .95 grams. The male is also more slender than the female, whose abdomen is broad in comparison to his. Another difference between the male and female of the species is that while the male has wings that almost reach the abbomen, the female only has pads as her wings. Although both have wings or pads, neither can fly. The nymphs have a similar shape to the adults, but unlike the adults, are wingless (Cornwell 1976; Lyon 2000).
Range mass: .45 to .95 g.