The bold white spectacles of the Plumbeous Vireo are also shared by the Blue-headed and Cassin's Vireos but they have more contrast between the gray head and the more olive back and olive or yellowish flanks. Black-capped Vireo also has white spectacles but it has a black, not gray, head. Yellow-throated and White-eyed Vireos have yellow spectacles. The Gray Vireo is similar but it lacks spectacles and has faint wing bars.
Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.