In this work, the simultaneous solubility of a gas mixture of CO2 + H2S (70 + 30 mol%) into the aqueous solutions of N-methyldiethanolamine (MDEA) blended with 1-butyl-3-methylimidazolium acetate [bmim][acetate] is measured using a static high pressure equilibrium cell. The solvent mixture consists of MDEA (30, 50 wt%) and [bmim][acetate] (5, 10, 50 wt%). The experiments are carried out at 323.15 and 348.15 K and in total pressure range of about 2-25 bar. The solubility data is tabulated and presented as acid gas partial pressures against its molality and mole fraction. The results illustrate that an increase in temperature and decrease in MDEA concentration lead to lower solubility of the both acid gases. At low ionic liquid mass fractions region, increasing [bmim][acetate] cause to reduce solubility of the both acid gases. Nevertheless at high IL mass fraction, the reduction of CO2 solubility is observed, but for H2S extend of its solubility depends on temperature. In the other words, more increase in ionic liquid leads to enhance H2S solubility through reduction temperature; and at given ionic liquid (IL) weight percent, the H2S solubility is reduced by increasing temperature. Finally, it can be concluded in the presence of CO2 the selectivity of MDEA + IL is toward H2S at all IL weight fractions. (C) 2015 Elsevier B.V. All rights reserved.