Abstract: A filtering, water eliminating and lubricating compressed air valve structure includes a compact air valve installed between a conventional air compressor and a pneumatic tool. A filter element is positioned inside the air inlet fitting of the compact air valve and, after a transparent condensate chamber is installed over the air inlet fitting, a washer mount and a filter ring are inserted over the bottom of a cross-shaped annular connector, at the bottom of which is a hollow neck that is in continuity with its tubular circumferential wall. A plurality of passages in the lower circumferential end of the hollow neck are disposed in continuity with a throat at the top and a threaded hole, enabling the installation of an lubricating oil reservoir on the upper half of the cross-shaped annular connector.