Measurements of the enthalpy of solution for carbon dioxide in (water + monoethanolamine, or diethanolamine, or N-methyldiethanolamine) and in (water + monoethanolamine + N-methyldiethanolamine) at T = 298.15 K have been made by isothermal displacement calorimetry. The estimated uncertainty is between +/-1 and 2 per cent. The results are compared with previous measurements made by isothermal flow calorimetry, isoperibol calorimetry and values derived from solubility measurements.