The liquid scintillation counting properties of several high- and low-energy radioisotopes in a proprietary solubilizer-scintillator mixture have been studied. Unquenched aqueous solutions of 14C, 3H, 65Zn, 60Co, 144Ce, 133Ba and 36Cl were counted at reasonable efficiencies, and the effects of several quenching agents on counting efficiency were determined. The counting mixture, typical of several others also available, was more effective in solubilizing and counting large amounts of aqueous sample than a conventional dioxane based counting solution. The feasibility of using a solubilizer-scintillator mixture to count aqueous solutions of unconventional radioisotopes in a liquid spectrometer has been demonstrated.