A device and method is disclosed for delivering NO to a patient. The device utilizes a single controller that controls two separate flow controllers to deliver an oxygen-containing gas and a NO-containing gas to the patient to provide NO-containing gas at a flow profile that is proportional or quasi-proportional to a flow profile of the oxygen-containing gas throughout patient inspiration. The controller further comprises logic for setting a nitric oxide delivery profile comprising at least two different concentrations of nitric oxide containing gas and for automatically switching between the at least two different concentrations of nitric oxide containing gas on a timed basis.