The concept of the Culex vishnui complex in Southeast Asia is reviewed with a primary objective to clarify the definition of the group with respect to its species composition on the basis of the morphology of all stages. With this revised interpretation, it should be better to recognize this complex as a subgroup of the Sitiens Group and to subdivide this subgroup into 3 complexes as follows: (1) vishnui complex (sensu stricto) with vishnui (including annulus form in Southeast Asia), pseudovishnui (including neovishnui form), perplexus, alienus and incognitus; (2) tritaeniorhynchus complex with tritaeniorhynchus and its infraspecific form summorosus and (3) whitei complex with whitei and probably one other infraspecific form. A summary of the diagnostic characters of vishnui, pseudovishnui and tritaeniorhynchus and a brief discussion of their current status is provided.