Nonaqueous and aqueous mixtures of methyldiethanolamine and monoethylene glycol form promising absorbents for the combined hydrogen sulfide removal and I hydrate control, necessary in natural gas processing. In this direction, the density and viscosity of the binary and ternary systems were measured and modeled in the temperature range of T = 283.15-353.15 K and at ambient pressure. Excess molar volumes and viscosity deviations from ideality were also calculated. The water content varied from 5 to 50 wt % and the amine content from 5 to 90 wt %. Both density and viscosity were modeled using nonrandom two-liquid-based models. Regarding the density modeling, the average absolute relative deviations (AARDs) were found to be less than 0.4% for the binary subsystems and equal to 0.3% for the ternary system. Viscosity modeling results show higher AARD, though always lower than 3.0% for both binary and ternary solutions.