The invention provides a wet vacuum attachment, connecting to a hose of a commercially available vacuum cleaner that separates a liquid from a suction airstream created by the vacuum, so that the liquid does not enter the vacuum cleaner intake hose. The attachment can be manufactured as a single-part, having a suction port where the vacuum hose is attached, a suction passage to communicate with a reservoir in a region of low velocity for the separation and storage of the collected liquid, an inlet nozzle to increase the airstream velocity and to engage the working surface. In an additional embodiment, a filter media is inserted into a filter housing located in the region of low velocity between the suction passage and the reservoir to further prevent liquid from entering the vacuum hose.