This article describes a circularly polarized multiband microstrip patch antenna for ITS applications. The proposed antenna works for six band. The proposed antenna can be used for Dedicated Short Range Communication, Global Positioning System, WiMAX, etc. It has a modified T shaped patch and a defected ground for improved performance. The proposed antenna at 5.9 GHz frequency gives 17% of bandwidth, which makes it suitable for modern ITS applications. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2814–2818, 2016