Purpose: The purpose of the study was to investigate how much understand about artificial hydration in patients with terminal cancer, according to the subject groups, including patients, families, and general public. Methods: Data were collected from June 2007 to December 2007 and the participants included 22 hospitalized patients in the hospice unit of S Hospital, 100 families, and 101 participants who participated in a hospice education program for the general public. The questionnaire was developed through literature review, interview with patients' families, and expertise consultation. Data were analyzed using descriptive statistics with an SAS program. Results: Understanding of artificial hydration among patients, families and general public was examined from three perspectives. From an ethical perspective, 'if you receive artificial hydration, you can live longer', 45.5%, 63%, and 52.4% of the above three groups, respectively, answered "yes". From an emotional perspective, 'artificial hydration must be provided', 81.8%, 70% and 58.4%, respectively, agreed. From a cultural perspective, 'if artificial hydration is not provided for the patient, the families will feel painful', 95.5%, 83%, and 88.2%, respectively, answered "yes". Conclusion: This study found the differences in understanding of artificial hydration among patients, families and general public, and also found that less than 50 percent of the participants understood artificial hydration appropriately. We suggest, therefore, that patients' understanding about artificial hydration should be determined in the clinical setting and then followed by individualized education according to given medical situations.