A novel photonic bandgap (PBG) microstrip line is proposed for 50Ω conventional microstrip line. The proposed structure is fabricated with a periodic rectangle etched on the edge of the conductor line, and a flat and low-rippled passband is obtained. The characteristics of the novel PBG microstrip line are improved, as compared those of the conventional PBG microstrip line with holes etched in the conductor line or in the ground plane. The width of the stopband or passband can be changed according to the requirements. The measurement data of this novel PBG microstrip line agree well with the simulations. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 548–550, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20875