Sažetak Ethical principles along with legal systems are the most potent regulators of man’s behavior in collective life. They are two basic drives of civilization. Author gives a short analysis of foundation of ethical reasoning and its effects on individual and collective behavior. Medical profession is highly charged with moral responsibilities and duties. Ten heterogenous groups of ethical concerns have been identified in medicine. In order to ensure the professional performance according to ethical demands, medical profession is under permanent careful scrutiny. Author discusses the influeces of scientific progress and unusual circumstances on physicians profession and ethical concerns. The professional oath imposes the criteria of ethical standards which extends beyond the framework of medicine. Author records that, during the war in Croatia in years 1991-92, medical professionals have acted in accordance with ethical standards of the medical oath, even under the most severe attacks targetted on hospitals. He thinks, that fact will be recognized as improvement of ethical standards. Author proposes a recognition of preconceived and deliberate attacks on the hospitals as a new category of war criminal acts against humanity.