The idea of this project is to sense the alcohol content in the blood of a person through its breath. The breathalyzer is made with the help of MQ-3 sensor that is interfaced with a mobile phone. The MQ-3 sensor will provide a reading based on concentration of alcohol in the breath of a driver. An android application is developed that has the functionality of capturing the picture of the guilty, storing the guilty personal information, place, time and date of incident. The android application gives the reading in terms of %BAC (Blood Alcohol Content). MQ-3 is calibrated using the regression table which provide corresponding ppm value for the analog output of MQ-3.