Paraboreochlus stahlisp. n. is described from collections in small streams of northwestern Pennsylvania, U.S.A. The larva (presumed), pupa, female (partial) and male are discussed and illustrated.P. stahliis only the second species known for the genus and is the first described species ofParaboreochlusfrom outside the Palaearctic. A differential diagnosis forP. stahliandP. minutissimus(Strobl) Edwards indicates distinct differences for the larva, pupa and male of these two species. The partial description of the female ofP. stahliis the first for the genus.