A printed ultra-wideband (UWB) antenna with five notched stop bands is presented. By introducing a pair of arc-shaped slots, two defected ground structures and an open-loop resonator, five sharp notches are achieved at frequencies of 2.4, 3.2, 5.2, 5.8 and 7.5 GHz. The proposed antenna has been fabricated and tested. The measured results indicate that the proposed design not only supports UWB bandwidth requirements but rejects five narrow bands to avoid possible interference with existing communication systems. In addition, the proposed antenna has relatively omnidirectional radiation patterns in passbands.