Abstract: A nasal irrigator mainly includes a saline container having an upward inclined bottom conduit, a lower cap connected to a free end of the conduit, and a plug fitted around a front tube portion of the lower cap for extending into a patient's nostril. The tube portion of the lower cap is provided around an outer periphery of a front end with an annular rib. A stopper is fixed in and projected forward from the front end of the tube portion such that a passage is formed between the stopper and the tube portion. The plug has a front head portion provided with an axial through hole and a rear sleeve portion adapted to fitly put around the tube portion of the lower cap. The plug may be pushed toward the lower cap so that the stopper extends into and blocks the through hole of the plug, and saline in the container could not be supplied into the plug via the through hole.