The densities of the ternary systems (methyltrioctylammonium bis(trifluoromethylsulfonyl)imide + ethanol + methyl acetate, or ethyl acetate) have been measured at the T = (298.15, 303.15, and 313.15) K. The ionic liquid (IL) methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([MOA](+)[Tf2N](-)) was used. The ternary excess molar volumes, V-123(E), were calculated from the experimental densities at each temperature. The V-123(E) values are negative for all mole fractions of the IL. For the system {[MOA](+)[Tf2N](-) + ethanol + methyl acetate), the minimum ternary excess molar volume, V-123 min(E), decreases with decreasing z values (increasing mole fraction of IL) except at z = 0.10 at T = 298.15 K. The V-123 min(E) decreases with an increase in the temperature except at z = 4.00 at T = 303.15 K. For the system {[MOA](+)[Tf2N](-) + ethanol + ethyl acetate} V-123 min(E) increases with decreasing z values at each temperature. The V-123 (E)(min) decreases with an increase in the temperature except at z = 0.40 at T = 313.15 K and at z = 0.08 at T = (303.15 and 313.15) K where it increases. The Cibulka equation was used to correlate the ternary V-123(E), data using the Redlich-Kister parameters obtained from fitting the Redlich-Kister equation to the five binary systems obtained from literature. (C) 2010 Elsevier Ltd. All rights reserved.