Liquid-liquid equilibrium data for the ternary system water + ethanol + 1-decanol have been measured at (2, 15, and 25) degrees C, with two different methods of analysis: refractive index and gas chromatography. A small region with three phases (solid-liquid-liquid) and two regions with two phases (solid-liquid) appear at 2 degrees C. Liquid-liquid regions show quite similar shapes at all of the temperatures.