Informed consent is currently an ethical, medical and legal requirement. Increasing public discussion concerning real or supposed malpractice has caused patients to adopt a critical attitude and has caused courts to increasingly demand informed consent for patients. Unfortunately, the legal requirements for informed consent have developed from atypical situations involving dissatisfied and injured patients rather than from the more common occurrence of physicians helping patients and having satisfied patients. In addition, the law has failed to establish explicit guidelines for physicians. We review the elements of informed consent based on current Austrian and German jurisdiction in the particular field of oncology and summarise the legal and medical realities with the aim of delineating specific criteria for decision making.