Experimental measurements of dew points for ternary ethane + water + methanol were carried out between 0.98 x 10(5) and 22.36 x 10(5) Pa and the temperature range from 246.90 to 283.06 K. An EOS-CR method (equation of state-chemical reticular) reproduces quite accurately the experimental data within average absolute deviation (AAD) from 0.05 to 4.12 K.