The amount of medical information is rapidly increasing in accordance with the development of medical technology. Therefore, developing efficient ways of management, exchange and sharing of medical information is becoming an important issue. A variety of models and tools introduced in hospitals, departments and clinics became obstacles in the reproduction and utilization of information. A proficient means of exchanging this medical information, known as an Application Program Interface (API) has been designed in the present study. A discharge summary which contains major description of medical care has been chosen as the source for this exchange. The API translated the information on the discharge summary into Health Level Seven (HL7) messages, which is the standard protocol for exchanging information. Users could send and/or receive a discharge summary using a web browser using this API. For the security of a web-server, we used a freeware, Mr.Flux, to control access to the server. Time to input data was significantly different according to the traffic of network, which was 341±55 seconds and 131±15 seconds at 10 p.m at 10 a.m. In summary, HL7 based on an API for the exchange of information on nuclear medical care could be used in different computing environments such as an internet based system that is convenient to use for most users.