The term informed consent does not have long historical roots. Until recent centuries, healthcare professionals were not held responsible for providing information to patients. The author reports a written consent from Anatolia dated almost five centuries ago. The contract was signed in 1539 in Gaziantep, Turkey (formerly known as Aintab, Ottoman Empire). The document, of course, differs from modern counterparts. It lacks details of interventions. The author believes this to be the first written consent in medical history. Further investigations of court registers should be made to ascertain the earliest date of their appearance.