Empirical standard weight equations and length-weight and length-length relationships were estimated for Barbus pergamonensis, Capoeta bergamae, and Ladigesocypris irideus, three endemic cyprinid species of Turkey that are still not widely studied. To the best knowledge of the authors, empirical standard weight equations for the three species and L-W parameters for L. irideus are given here for the first time. In this study, length and weight data for B. pergamonensis, C. bergamae, and L. irideus were collected throughout the watercourses of Mugla Province and were used to develop species-specific W-s equations. The results were for B. pergamonensis (total length [TL] range: 6-22 cm) log(10)W(s) = -5.713 + 3.718 log(10)TL - 0.166 (log(10)TL)(2), for C. bergamae (TL range: 8-29 cm) log(10)W(s) = -5.224 + 3.311 log(10)TL - 0.083 (log(10)TL)(2), and for L. irideus (TL range: 6-10 cm) log(10)W(s) = -13.298 + 12.116 log(10)TL - 2.471 (log(10)TL)(2). This study also reported new maximum TLs for the three species, together with species-specific length-weight and length-length equations.