Informed consent is a question of central importance in contemporary medical ethics, and clinical practice is inconceivable without considering the issues it raises. Although it is often vigorously argued that consent, informed or otherwise, is a recent phenomenon and that no sources testify to its existence before the 20th century, it is difficult to accept that a process for regulating the common and fundamental parameters in the relationship between doctor and patient and the planning of treatment had not concerned previous eras. A review of the Registers of the Islamic Court of Candia (Heraklion) in Crete, a series of records that touches on, among other things, matters of medical interest, reveals that the concept of informed consent was not only known during a period that stretched from the mid-17th to the early 19th century, but it was concerned with the same principles that prevail or have been a point of contention today. An extension of this study into other periods may thus provide contemporary researchers with material and information valuable in the discussion of today's bioethical issues.