The knowledge of freshwater fishes in remote Andean mountains is scarce and restricted to changes of occurrence distribution along a specific gradient. The high number of endemic fish species requires further studies regarding their biology and their conservation status. The present study aims to estimate the length-weight, length-length, and length-girth relations for nine native freshwater fish species representing five families (Loricariidae, Characidae, Heptapteridae, Crenuchidae, and Parodontidae): Chaetostoma thomsoni Regan, 1904; Lasiancistrus caucanus Eigenmann, 1912; Rineloricaria jubata (Boulenger, 1902); Bryconamericus huilae Roman-Valencia, 2003; Gephyrocharax melanocheir Eigenmann, 1912; Pimelodella chagresi (Steindachner, 1876); Rhamdia guatemalensis (Quoy et Gaimard, 1824); Characidium fasciatum Reinhardt, 1867; Parodon suborbitalis Valenciennes, 1850. The fishes were collected in the Suaza River (Huila, Colombia). These are the first length-weight relations reported for all these species, mostly endemic to the Colombian Andes. The report also provides the new maximum size for four species.