This Project describes a design of an effective vehicular parameter monitoring system through GSM. A GSM modem provides the communication interface. It transports device protocols transparently over the network through a serial interface. A GSM modem is a wireless modem that works with a GSM wireless network. This GSM Modem can accept any GSM network operator SIM card and act just like a mobile phone with its own unique phone number. Advantage of using this modem will be that you can use its RS232 port to communicate and develop embedded applications. Applications like SMS Control, data transfer, remote control and logging can be developed easily. The modem can either be connected to PC serial port directly or to any microcontroller. This project is built on 8051 micro controller, in this project a micro controller is interfaced with a GSM modem via serial interface, few sensors are interfaced to the micro controller which are continuously monitored, whenever a sensors sends an abnormal value or a value above the threshold value, immediately a the information is sent to the concerned mobile number in the code. Using this project we can continuously track the vehicle and also the status of the vehicle like the fuel level, air bag status, door open/close status, temperature etc. This project uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Full wave bridge rectifier is used to rectify the ac output of secondary of 230/12V step down transformer.