A new species of nemachilid loach Aborichthys barapensis, is described based on two adult specimens (91 and 97 mm SL) from the Barap Stream (a tributary of the Brahmaputra River basin) in the southeastern most part of the state of Arunachal Pradesh bordering Myanmar. The new species is distinguished from its congeners in having a narrow black basicaudal bar without a black ocellus on the upper end (vs. present); and in having a very low dorsal and ventral adipose crests (vs. prominent; absent in A. waikhomi). The new species is further distinguished from its congeners by the following combination of characters: body with 24-26 oblique bars along the flank; interspace narrower than bars on body; moderately rounded caudal fin with five distinct black to brown cross bars; vent closer to the caudal-fin base (44.1-45.1 % standard length) than to snout tip. © 2021 Nanda & Tamang. All Rights Reserved.