This article describes a novel design and development of hybrid monopole rectangular microstrip antenna (HMRMSA) for WLAN and Wi-MAX applications. This antenna operates for the frequency range of2.07 to 6.72 GHz and showing a impedance bandwidth of 145%. The antenna structure consists of hybrid triangular shape model. At the bottom surface a partially ground plane is placed to achieve single wideband. The proposed antenna is fabricated using low cost FR4 substrate material. The antenna is excited through 50 ? microstrip line. The simulated and experimental results are demonstrates which are in good agreement with each other.The proposed antenna satisfies the -10dB impedance bandwidth requirements tocovering WLAN and Wi-MAX applications