Abstract: Novel pharmaceutical compositions of uridine 5'-triphosphate (UTP) for use in promoting increased mucociliary clearance of retained mucous secretions of the human airways, middle/inner ears or sinuses are disclosed. Novel Formulation I comprises UTP and aqueous solution having a therapeutic concentration between 5 and 45 mg/mL, a controlled tonicity within the range of 250 to 100 mOsM, a pH between 7.0 and 7.5, and is sterile. The pH-adjusted composition is capable of long-term storage in the refrigerated state with a shelf life of up to 30 months. Formulation I may be delivered therapeutically either in a nebulized form or in a liquid form. Novel Formulation II comprises UTP in an aqueous solution or suspension having a therapeutic concentration approaching the limit of UTP's solubility at ambient temperature. This high concentration allows delivery of a therapeutic amount of UTP in very small volumes (50 to 100 .mu.L) suitable for administration via portable hand-held devices such as metered dose inhalers.