Propagation of wireless technologies, mobile computing devices, and the Internet has provided an opportunity to develop and deliver new types of location-based applications and services to users. This paper presents a prototype application of internal location-based service using passive RFID (Radio Frequency Identification) to determine location. We also address some of the issues, advantages and disadvantages of using RFID technology. The function of the system is based on strategically located passive RFID tags with exclusive identifiers placed around buildings which are identified using a RFID reader attached to a PDA or mobile phone. The phone reads the RFID tag and through the wireless network, sends the request to the server. The server resolves the request and sends the answer which is in different format back to the phone. The users will be able to locate their position by reading the RFID tag and selecting the query or information desired.