The length-weight relationships for 10 freshwater fish species from an intermittent river basin in a semi-arid region of Brazil were analyzed. Specimens were caught using a dragnet (3.5 × 2.5; stretched mesh size 5 mm) during running and pool phases from January to November 2015. The specimens were measured for total length and weight. Previously unavailable in FishBase, the detailed length-weight relationships of Compsura heterura, Phenacogaster calverti, and Serrapinnus piaba are reported for the first time. All fish collected presented total lengths ( TL) lower than the maximum reported in FishBase. [ABSTRACT FROM AUTHOR]