The upper side of the wings is blackish-brown with both wings having a yellow postmedian band and a yellow submarginal band. There is a yellow bar at the end of the fore wing cell. The underside of the wings is black with the fore wing having a yellow postmedian band and a yellow submarginal band. The hind wing has a few colored bands; the first being cream; the second, orange; the third, blue; and the fourth, orange. There is a yellow streak on the inner margin of the hind wing which runs parallel to the body. The wingspan ranges from 4½ to 5⅛ inches.
Males seek females by patrolling near forest edges and forest openings. In courtship, the male and female will fly about a foot apart, slowly flying together in unison. The male will then fly above and behind the female to disperse his pheromones and he will continue to do this until the female decides to mate with him. Females lay their pale greenish-yellow eggs singly on host plant leaves. The larva is green with two false eye spots on the thorax. It has a few blue spots on the first abdominal segment to the eighth segment. It also lives in a leaf shelter. (The larva is almost identical to the caterpillar of the Spicebush Swallowtail (Papilio troilus) except the Spicebush Swallowtail larva has larger false eyes, larger blue spots, and has different host plant preferences.) The green chrysalis has a whitish lateral stripe edged with brown above and has two horns on the head. The chrysalis hibernates. The Palamedes Swallowtail has 2-3 broods per year.
Here is a list of host plants used by the Palamedes Swallowtail:
- Jim P. Brock and Kenn Kaufman (2003). Butterflies of North America. Houghton Mifflin, New York, NY. ISBN 0-618-15312-8
- Rick Cech and Guy Tudor (2005). Butterflies of the East Coast. Princeton University Press, Princeton, NJ. ISBN 0-691-09055-6
- "Palamedes Swallowtail"  accessed on May 13, 2009
- James A. Scott (1986). The Butterflies of North America. Stanford University Press, Stanford, CA. ISBN 0-8047-2013-4
- Thomas J. Allen, Jim P. Brock, Jeffrey Glassberg (2005). Caterpillars in the Field and Garden. Oxford University Press, New York, NY. ISBN 978-0-19-514987-6
- David L. Wagner (2005). Caterpillars of Eastern North America. Princeton University Press, Princeton, NJ. ISBN 0-691-12144-3