A flow mixing unit adapted to a Setaram C-80 calorimeter was used for measuring enthalpies of absorption of carbon dioxide in a 30 wt % aqueous solution of monoethanolamine (MEA) at three temperatures (313.15, 353.15, and 393.15 K) and three pressures (2.0, 5.0, and 10.0 MPa). Determinations were performed both in the region where the gas is fully absorbed in the solvent and also in the region of concentrations above the saturation. Experimental data served to obtain the integral enthalpies of absorption and for indirect determination of solubility limits. Where comparison was possible, the presented results derived from calorimetric determinations were in reasonable agreement with those obtained from phase equilibria measurements.