Larvae of three genera representing the staphylinid subfamily Pseudopsinae are described for the first time and illustrated with 33 morphological drawings: Pseudopsis Newman, Zalobius LeConte and Nanobius Herman. Thirty-six characters (mainly of larval morphology) were scored for representatives of six staphylinid subfamilies and a phylogenetic analysis was carried out. The monophyly of the subfamily Pseudopsinae is supported by the presence of a short oblique ridge on ventral side of larval head capsule laterad of maxillary foramina. The monophyly of each of the subfamilies Paederinae and Staphylininae is discussed based on the characters of the immature stages. The subfamily Pseudopsinae is confirmed to be a sister-group of the subfamilies Paederinae + Staphylininae on the basis of six larval synapomorphies. The latter clade is confirmed to be monophyletic on the basis of five larval synapomorphies. A larval identification key to the studied Pseudopsinae genera is provided.