In the present work, DESs composed of choline chloride (ChCl), glycerol and l-arginine at various molar ratios were synthesized and the effect of temperatures and molar ratios of glycerol and l-arginine on their physical properties were studied. Densities and viscosities were measured at the temperature range from 298.15 K to 343.15 K, whereas refractive index was measured at 298.15 K to 333.15 K. The density values were used to estimate thermal expansion coefficients while the viscosity values were used to estimate activation energies. The thermal stability of the mixtures was found to be more dependent on the concentration of glycerol and l-arginine. © 2015 Elsevier B.V. All rights reserved.