A liquid dispenser includes a pressing unit is pivotably connected to a base received in a body. A guiding tube in communication with a container is movably connected to an engagement cap. An inner tube includes a passage in communication with a passage of an outer tube. The inner tube further includes at least one hole in communication with the passage of the inner tube and a passage of the guiding tube. A mouth includes a tube and an end cap having an aperture. The tube includes two rods movably engaged in two sliding grooves of the pressing unit. The tube is coupled to the outer tube, with the aperture of the end cap in communication with the passage of the outer tube. When the pressing unit is pressed, the transverse rods are driven by the sliding grooves to move upward, causing dispensation of a fluid via the aperture.