A method and system for generating and delivering nitric oxide directly to a patient. A reaction chamber is provided that is located at or in close proximity to the patient and reactants within the reaction chamber react together to produce a predetermined amount of nitric oxide. The reaction is controlled by metering at least one of the reactants into the reaction chamber to generate a predetermined quantity of nitric oxide as required by the patient. The reactants can include a nitrite salt, such as sodium nitrite, and a reductant such as ascorbic acid, maleic acid or a mixture thereof. By generating and delivering the nitric oxide directly to the patient in close proximity thereto, the formation of NO2 is minimized. One or both of the reactants may be in liquid form.