Densities and refractive indices have been measured for glycylglycine in aqueous FeCl2 solution as a function of concentration at T = (288.15 to 318.15) K. The apparent molar volumes and partial molar volumes were obtained from these density data. The limited partial molar expansivities have been calculated from the temperature dependence of the partial molar volume. The molar refractions were calculated from the experimental refractive index values for the studied mixture. The excess volumes and molar refractions were also calculated. The results are discussed in terms of molecular interactions.