In spite of a referral letter as an important document for communicating between physicians, whether it could also be useful as a source of information for patients has not yet established. We included cancer patients in palliative care setting, all of whom completed a standardized questionnaire regarding their opinion concerning the utility of a referral letter as a source of information and its requirements to achieve a better understanding. Completed questionnaires were received from 50 cancer patients. Ninety-four percent of participants agreed that a referral letter could be of great importance for procuring medical information to them. There was only minor divergence among the participants respecting age, gender, or education. Particular requirements were diagnosis, treatment plan, prognosis, list of drugs, and contact data of involved physicians. Additional important topics were laboratory values, alternatives to current therapy, side effects and supportive therapy, and advices regarding lifestyle and naturopathy. The majority of patients also concluded to accept technical terms in doctor's letters if a glossary supported their comprehension. The majority of patients prefer a concise description of medical information in a referral letter. This form of a letter would boost patients' involvement and help them transfer medical information to other therapists or relatives.