West Nile virus (WNV) has recently been associated with a syndrome of acute flaccid paralysis. Most cases of WNV-associated weakness have clinical, histopathologic, and electrophysiologic characteristics indistinguishable from those of poliomyelitis caused by infection with poliovirus. There is debate about the nomenclature of this manifestation of WNV infection. An historical perspective of the term "poliomyelitis" suggests that the term "WNV poliomyelitis" seems appropriate, but members of the neurologic and infectious disease communities should engage in discussion regarding the terminology of this syndrome.