Since the year 2000, lung cancer has become the leading cause of cancer death in South Korea as in many other parts of the world. The current multidisciplinary approach for lung cancer includes a wide range of modalities, not only surgery, radiotherapy, medical drug therapy but also pain control, as well as social and psychological support. Therefore, thoracic surgeons, radiologists, nuclear medicine specialists, anesthetists, psychologist, nurses and social workers as well as medical doctors care for lung cancer patients. Sharing a common treatment protocol and optimal communication are vital aspects of shared care both from a medical and cost-effectiveness point of view. We developed a shared electronic medical record (SEMR) for treating patients with lung cancer in a university hospital to facilitate the sharing protocols and communications between doctors involved in a lung cancer clinic. A SEMR system was developed within a order communication system(OCS) for a lung cancer clinic. The records of radiological, laboratory and pathological studies as well as the records of surgery, chemotherapy, and radiotherapy were stored and presented to all doctors who treat the same patient. Every doctor was allowed to change his/her own records. They could review other doctors records but could not alter them. With the SEMR, it was expected that the time to complete the medical records for one patient could be reduced because it was easy to review all the data from the other doctors who share the same patient. In addition, the confidence of the doctors who share a common treatment protocol would be higher. Therefore, a shared electronic medical record is expected to improve the quality of patient care.