Revealing medical secrets is one of the most important topics in medical law, and has an ancient root in medical history and morality. Keeping patients' secrets is one of the certain laws in internal and international laws and regulations of the most countries that have been recognized in patients' bill of rights. Keeping patients' secrets causes patients to confide in physicians and refer to them disregard of this, causes unreliability of patients towards physicians and the lack of visiting them. Using medical records without patient's permission is not lawful except the cases or the places where law allows for continuing his treatment or medical researches. Breach of this obligation, may cause harm to patient so the domain of civil liability due to revealing medical secrets in Iran's law and common law countries that have recognized this fact officially and the cases that make physicians legally or morally bound to keep patients' secrets, are known and examined. Also the cases that physicians are allowed to reveal patients' secrets are stated. In spite of recognizing civil liability for revealing medical secrets and terms of liability and compensation for damages legislatively in our country at compensation for damages due to revealing medical secrets, comparative studies about this subject with Iran's law can be helpful. We don't see such claims and orders in Iran's judicial system practically and we need information and codification of up-to-date rules and regulations about it. Paying more attention to this fact is necessary, because keeping people's privacy in today's world, regarding ever-increase development of technology and communications industry have been very important and such topics are today's society needs.