This work reports experimental phase equilibrium data for the ternary system involving epsilon-caprolactone, carbon dioxide, and dichloromethane. Such data provide fundamental information to conduct polymerization reactions in supercritical carbon dioxide medium. The experiments were performed using a variable-volume view cell over the temperature range from 323.15 to 353.15 K and different mass ratios of dichloromethane to epsilon-caprolactone (0.5:1, 1:1, and 2:1). Phase transitions of vapor liquid at the bubble point (VLE-PB), liquid liquid (LLE), and vapor liquid liquid (VLLE) types were observed. The experimental results were modeled using the Peng-Robinson EoS with the van der Waals mixing rule, resulting in a good representation of experimental phase equilibrium data.