The Japanese Society of Palliative Medicine has developed a clinical guideline to minimize the large variation in clinical practice of artificial hydration therapy for terminally ill cancer patients. The primary aim of this preliminary study was to explore the effects of a five-hour interactive workshop based on the guideline of nurses' knowledge, confidence, self-reported practice, and nurse-perceived usefulness. The study was designed as a pre-post anonymous questionnaire survey. The nurses attended a five-hour interactive workshop based on the guideline and were asked to complete a questionnaire before and after the workshop. The outcome measures were: nurses' knowledge (13 items; the total number of correct answers was defined as the Knowledge score), confidence in caring for terminally ill cancer patients with reduced oral intake (a single Likert-type scale from 1="not confident at all" to 7="very confident"), and self-reported practice (nine items assessing the degree to which nurses think they would perform more frequently recommended practices described in the guideline after the workshop). Of the 81 nurses who participated in this workshop, we obtained consent from 76 to complete the questionnaire. The Knowledge score significantly increased after the intervention from 7.7+/-2.3 to 11+/-1.4 (P<0.001), and the Confidence score significantly increased from 3.1+/-1.2 to 3.8+/-1.1 (P<0.001). More than 80% of the nurses reported they would perform six of nine recommended practices after the workshop. The percentages of nurses who evaluated this workshop as "useful" or "very useful" were: 84% (to know the medical indications of artificial hydration therapy), 89% (to know the effects of artificial hydration therapy on patient quality of life and survival), 71% (to know the physiology of appetite loss and cancer cachexia), 83% (to know how to provide nursing care), and 91% (to know ethical principles). Based on these results, it is possible that a five-hour interactive workshop on artificial hydration therapy, based on the clinical guideline of the Japanese Society of Palliative Medicine, improves nurses' knowledge, confidence, and self-reported practices. The workshop was generally perceived as useful for nurses. Nationwide dissemination of the guideline with interactive workshop education for nurses, in combination with physicians, is a promising method for improving the clinical practice of artificial hydration therapy for terminally ill cancer patients.