A high-pressure-cell technique based on the analytical method was used to investigate the simultaneous solubility of the chemically reacting gases ammonia and carbon dioxide in solvent mixtures of (water + methanol). Seven (gas-free) solvent compositions were considered (methanol mole fractions of about 0, 0.05, 0.25, 0.5, 0.75, 0.95, and 1). The temperatures were approximately (313, 353, and 393) K. In the isothermal experimental series, carbon dioxide was added stepwise to a cell containing a mixture of (water + methanol + ammonia). The stoichiometric molality of ammonia in the solvent mixture of (water + methanol) was approximately (6 and 12) mol. (kg of solvent mixture)(-1). The carbon dioxide loading (i.e., the ratio of the stoichiometric molalities of carbon dioxide and ammonia) ranged up to 1.07. The total pressure ranged up to 5.5 MPa. Vapor-liquid equilibrium data, including partial pressures of all components, are reported.