Abstract: A combination spirometer or peak flow meter and nebulizer system is provided. Utilization of common elements, on a time sharing basis is accomplished by the combined instrumentation. The sharing of a common chamber by a peak flow meter and a nebulizer system is controlled by valves operated in response to phases of the respiratory process of a patient. With this combination vaporized medication is provided to a patient for inhalation during the inhale phase of the respiration cycle and the effectiveness of the inhaled medication is monitored by measuring the rate of flow of the breath exhaled during the exhale phase of the same respiratory cycle.