Abstract: A portable oral irrigator includes a nozzle, a handle, an outer water container and an inner water container. The nozzle is at an upper end of the portable oral irrigator. The handle is below the nozzle. The outer water container is below the handle. The inner water container is below the outer water container. A sealing ring is at a bottom of the inner water container for sealing the inner water container. An annular silicone sealing member is at a joining portion of the outer water container and the inner water container. A gasket is between the outer water container and the handle. An air passable silicone seal is on the gasket. With provision of the air passable silicone seal, a raised bottom of the air passable silicone seal contracts to close its cross-shaped opening due to water pressure in the outer water container, thereby preventing leakage.