Polyethylene cisterns for underground use with pump, also vertical, with variable capacity: from 1,021 to 10,700 litres. They have a smooth, thick surface or a corrugated surface, designed to suitably resist the thrust of the surrounding soil. The underground polyethylene tanks have provisions for loading, unloading and total emptying; the underground polyethylene tanks with a corrugated surface can be equipped with an upper passoduomo for inspection and are suitable for the containment and recovery of water.