Hemigrammus rubrostriatus spec. nov. from Colombia is described and H. falsus Meinken, 1958 is revalidated. Both are members of the H.-ocellifer-group according to Géry (1978). H. rubrostriatus spec. nov. is characterized by its coloration: (1) a vertically elongated humeral spot, (2) a vermilion longitudinal band, which runs from operculum along the body up to the dorsal part of the caudal peduncle and to the rays of caudal fin, (3) an elongated caudal spot, which is asymmetrically on the lower part of the caudal peduncle and the basis of caudal fin, sometimes up to the tips of the fin rays. Further characteristics: (1) lateral line with 10 to 15 pored scales relatively long, (2) 34 to 36 scales in a longitudinal row, (3) 6 / 1 / 3½ to 4 scales transversal before dorsal fin, (4) iii to iv, 19 to 21 anal fin rays, (5) one to four maxillary teeth (x = 2,32), (6) body depth 2,91 (2,70 to 3,26) times in standard length, (7) head length 3,99 (3,58 to 4,61) times in standard length and (8) dorsal fin begins before midbody. The Head-and-tail-light Fish, H. falsus Meinken, 1958, was synonymized by Frankel (2002) as a result of cross breeding with H. ocellifer (Steindachner, 1882). According to Frankel (2002) H. ocellifer exhibits two phenotypes associated with spotting at the base of the caudal fin, with the fish either possessing (H. o. ocellifer) or lacking (H. o. falsus) a prominent red spot in this region. But this is not correct. The red spot at the base of caudal fin was never a feature for the differentiation of the taxa. The results of Frankel (2002) have no influence on the status of the species H. falsus Meinken, 1958. For this reason the taxon has to be revalidated.