The purpose of this project is to provide a home security system using GSM technology. This system facilitates the house owners to monitor their home remotely from anywhere in the world through a single electronic eye. This system comprises of a Microcontroller based electronic eye monitoring system, which is a PIR sensor (Passive Infrared) that is used to detect the presence of human beings (thieves). Whenever an un-authorized entry is done, this system can dial-up or sends SMS alerts to the house owner or Police automatically using GSM modem. The system also capable of detecting leakage of gas, and fire and alerts the owner and respected authorities through SMS and also dial up. This system can be mounted at any place/room that needs to be monitored. For example the house owner can mount this electronic eye or PIR sensor at one of the corners of the room so that it can cover monitoring the entire room area. Whenever a human being enters inside the room, this system senses the Passive Infrared rays emitted from the human body. The system also monitors the LPG gas leakages using gas detection sensor, fire using temperature sensor, in any Industry or Home and if it exceeds the threshold level, it alerts. This sensors output is given to the Microcontroller for further processing. Microcontroller takes necessary action like sending SMS based alarm messages for twice and automatically dials to the pre-programmed phone numbers. The Microcontroller is programmed using Embedded C language. This system works well both at day and night (dark light) timing. The phone numbers to which this system should dial-up can be preprogrammed. By this way we can take the prevention steps before occurrence of the major fire accidents and we can avoid the human losses and financial losses. The application program for the microcontroller will be written in embedded ‘C’ and will be stored in the flash memory of the microcontroller.