There is an increasing demand for indoor positioning systems as location based services are becoming more and more widespread. However, this field of research has not yet achieved the same success as that of outdoor positioning. The objective of this project was to implement an indoor positioning system relying on Bluetooth technology, and to integrate it into the Global Positioning Module (GPM) developed at the Institute of Services Science at the University of Geneva. The system compares the signal strengths of surrounding Bluetooth devices to a database of measurements taken across the indoor area, in order to estimate the user's position. Through an evaluation of the system, an accuracy of approximately 1.5 meters has been obtained.