The group contribution method modified UNIFAC (Dortmund) has become very popular because of its large range of applicability and the reliable results predicted for vapor-liquid equilibria, solid-liquid equilibria, activity coefficients at infinite dilution, azeotropic data, and excess enthalpies over a wide temperature range. However, in a few cases, especially at high and low temperatures, poor results are obtained. To overcome this problem, the modified UNIFAC (Dortmund) parameters have been refitted to an extended database, Additionally, new groups for different amides, used as selective solvents, have been introduced. Altogether, 43 new or revised pairs of group interaction parameters for modified UNIFAC (Dortmund) are given.