Security is a major driver of computerized home automation systems today. With the development of network and automatic control technologies, a home security monitoring and alarm system has become more and more efficient and effective as technology advances.In this paper we have proposed a simple, low cost, low power method for implementing a wireless home security system, using the Zigbee (IEEE 802.15.4) standard. Our project architecture consists of sensor nodes deployed in various places throughout a structure, to provide security for that structure. The Zigbee modules act as end devices that monitor the sensors continuously and send the security status of each sensor to the coordinator node, which is connected to an Arduino Micro Controller Unit (MCU), which acts as the master brains of the system. Furthermore, the Arduino is also able to relay its security information to an Android App that we have developed to make remote system monitoring even easier for the user. In our project we have used the XBEE Pro series2 radios for RF communication, a PIR motion sensor, and a contact door sensor, an automated door lock, an Arduino MCU, and a specially designed Android App. The software has been implemented using the C programming language.Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than the author(s) must be honored. Abstracting with credit Figure 1: A Digi International zigbee wireless controller is 24.33mm in width, not much larger than a U.S. quarter.