The caridean shrimp genus Alvinocaris Williams and Chace, 1982 (Bresilioidea: Alvinocarididae) is revised based upon type material and newly obtained samples from various reducing environments of the deep‐sea floor of the world. All species are known from chemosynthetic communities associated with hydrothermal vents, brine or cold seeps. Eight named species are recognized in Alvinocaris, of which one is new, A. dissimilis sp. nov. from the hydrothermally influenced area of Minami‐Ensei Knoll, Mid‐Okinawa Trough. Alvinocaris dissimilis sp. nov. was confused with A. brevitelsonis in the original description of the latter species by Kikuchi and Hashimoto (2000). Seven previously described species (A. lusca Williams and Chace, 1982, A. markensis Williams, 1988, A. muricola Williams, 1988, A. stactophila Williams, 1988, A. longirostris Kikuchi and Ohta, 1995, A. brevitelsonis Kikuchi and Hashimoto, 2000, and A. williamsi Shank and Martin, 2003) are re‐described, and characters distinguishing these species are ...