The phase behavior of the ternary system consisting of the ionic liquid (IL) 1-hexyl-3-methylimidazolium tetrafluoroborate ([hmim(+)][BF4-]) + carbon dioxide (CO2) + methanol is studied experimentally using the Cailletet apparatus. Experimental data for all phase transitions within a temperature range of 254.64-348.17 K, a pressure range of 2.102-13.189 MPa and a CO2 fraction range of 40.20-69.98 mol% are collected, while the ratio [hmim(+)][BF4-]:methanol is kept constant at 1:19. Only at CO2 concentrations between 66.47 and 68.04% the usual 'two-phase'-'three-phase'-'two-phase'-'one-phase' transition upon CO2 pressure increase is found. At lower and higher CO2 fractions, the number of phase transitions observed is lower. All observed phase transitions do not involve criticality. (C) 2010 Published by Elsevier B.V.