The critical temperatures (T-c) and critical pressures (p(c)) of five binary mixtures (DEC + hexane, DEC + heptane, DEC + octane, DEC + cyclohexane, DEC + ethanol) and a ternary mixture (DEC + ethanol + heptane) were determined over the whole range of concentration using an accurate experimental apparatus based on flow method. The combined standard uncertainty of temperature is 0.2 K while that of pressure is 5.2 kPa. The critical temperatures of DEC + octane and DEC + cyclohexane mixtures present a non-ideal behavior. The maximum average absolute deviations of Redlich Kister equations for Tc and pc of five binary mixtures are 0.08% and 0.41%, respectively. Cibulka's equations and Singh Sharma's equations were used to correlate the critical parameters of ternary mixture. The critical surfaces of ternary mixture were plot using Cibulka's equations. (C) 2018 Elsevier B.V. All rights reserved.