Characters of the head of larvae of Gyrinidae were examined and evaluated phylogenetically. The groundplan of the family cannot be reconstructed as long as the larvae of Spanglerogyrus are unknown. The monophyly of Gyrinidae or Gyrininae is demonstrated by several autapomorphies such as the absence of a tentorial bridge and a completely divided prementum. Gyrinidae are the sistergroup of all other Adephaga. Partial reduction of the maxillary fossa, palpiform maxilla, and loss of one stipitopalpal muscles are synapomorphies of Adephaga excl. Gyrinidae. Presence of a series of small hooks proximal to the lacinia, and elongation of the prepharynx are possible autapomorphies of Gyrinini. The monophyly of the enhydrine genera + Orectochilini is supported by strong elongation of antennomeres and palpomeres, an improved mandibular channel, vestigial or absent retinaculum, and by a specialized prepharyngeal filter apparatus. The monophyly of Dineutus + Andogyrus + Macrogyrus is suggested by the extreme elongation of the cardines. Orectochilini are characterized by the presence of tormae and the absence of clypeolabral teeth.