Pethia poiensis, a new cyprinid species, is described from the Challou River, Chindwin Basin, Manipur, India. The new species is characterised by an incomplete lateral line with 7-9 pored scales, the absence of barbels, 19-20 scales in lateral series, 9-10 pre-dorsal scales, 18 pre-anal scales, 3½ scales between dorsal-fin origin and lateral line, three scales between lateral line and pelvic-fin origin and a unique colour pattern consisting of a humeral spot encompassing the third and fourth lateral-line scales, a caudal spot on the 16th and 17th lateral series scales and a black stripe along the flank. A revised key to the species of Pethia found in the Chindwin-Irrawaddy drainage is presented.
Keywords: Pisces, Pethia, Challou River, Chindwin-Irrawaddy drainage, India.