A poorly understood and partially described planktonic copepod, Labidocera gangetica Sewell, 1934, is fully described herein from the Hooghly River, a century after its initial collection from the Rangoon (now Yangon) River estuary by Sewell (1912). The complete description of L. gangetica suggests possible uncertainty regarding the validity of the species Labidocera jaafari Othman, 1986, due to the morphological similarity in their overall body plan. In particular, the features of the leg 5 of both sexes are identical, suggesting that L. jaafari is probably a synonym of L. gangetica. Additionally, the taxonomic features of the mouthparts and swimming legs are illustrated for the first time.