Liquid-liquid equilibrium (LLE) data are presented for ammonium based ionic liquids (ILs) + dibenzothiophene (DBT) + n-dodecane at 298.2 K and atmospheric pressure (similar to 95 kPa). Mole fractions were determined by the refractometry or graphical method. DBT phase distribution, ionic liquid selectivity, and DBT percent extraction were determined. Ionic liquids used here were compared with imidazolium in terms of sulfur removal. Hand and Othmer-Tobias correlations were used to test the LLE data and gave sigma < 0.09 (R-2 > 0.90). The nonrandom two-liquid model (NRTL) was used to correlate the LLE data, giving percent root-mean-square deviations < 0.22 between experimental and calculated mole fractions.