Abstract: A portable oral irrigator includes: a foldable container made of a flexible material and having a bottom wall, a peripheral wall connected to the bottom wall, and a receiving space defined jointly by the bottom wall and the peripheral wall, wherein the peripheral wall is circumferentially and concavely provided with a folding groove; a main unit connected to the bottom wall and having a water inlet tube in communication with the receiving space; and a nozzle unit having a connecting tube in communication with the water inlet tube and a nozzle connected to the connecting tube. The peripheral wall can be folded, and the nozzle unit can be received in the collapsed space defined jointly by the folded peripheral wall and the bottom wall, allowing the portable oral irrigator to be carried around with ease.