This article presents a split ring resonator (SRR) loaded triple band waveguide broad wall longitudinal slot array antenna. Three uniformly spaced SRRs have been placed on the transverse plane of a slotted rectangular waveguide. The measured result shows that the antenna has 10 dB return loss bandwidth of 8.38–8.62 GHz, 9.17–9.43 GHz, and 10.63–11.34 GHz. The gain and radiation pattern of the antenna are also plotted. The gain, cross polarization ratio, and front to back radiation ratio of the proposed antenna are found to be higher than that of a conventional broad wall longitudinal slot array antenna. An equivalent circuit of triple band antenna is also presented. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2500–2505, 2016. © 2016 Wiley Periodicals, Inc.