The invention provides compositions and methods for delivering carbon monoxide (CO) to subjects suffering from inflammatory, cardiovascular, Sickle Cell, and other disease. The compositions are liquids, including Newtonian and non-Newtonian liquids, such as pastes, gels, foams, emulsions, and other non-gaseous compositions, in which CO is dissolved at an amount that, when administered to a patient, provides a therapeutically or prophylactically effective amount of CO to the patient. The compositions can be provided in many forms, including in bottles or cans