New modified UNIFAC property prediction model parameters are reported for 89 main groups and 984 group-group interactions using critically evaluated phase equilibrium data including vapor-liquid equilibrium (VLE), liquid-liquid equilibrium (LLE), solid-liquid equilibrium (SLE), excess enthalpy (HE), infinite dilution activity coefficient (AINF) and excess heat capacity (CPE) data. The new algorithmic framework for quality assessment of phase equilibrium data is applied for qualifying the consistency of data and screening out possible erroneous data. Substantial improvement over previous versions of UNIFAC is observed due to inclusion of experimental data from recent publications and proper weighting based on a quality assessment procedure. The systems requiring further verification of phase equilibrium data were identified where insufficient number of experimental data points is available or where existing data are conflicting. Published by Elsevier B.V.