We investigated the influence of brines and NaCl alone at commensurate concentrations on three larval amphibian species that occur in areas with energy-related brine contamination. The dataset contains size information (mass in grams, snout-vent length in millimeters) of larval Boreal Chorus Frogs (Pseudacris maculata) and Northern Leopard Frogs (Rana pipiens) and Barred Tiger Salamanders (Ambystoma mavortium) taken during 96-h lethal-concentration-50 experiments. Larvae were generally exposed to concentrations of brine or NaCl ranging from 0–8,000 mg/L increasing by 1,000 mg/L increments.