The phrase "Primum non nocere" is almost as old as the practice of medicine. Together with the principles of beneficence, autonomy and justice, keeping in mind the confidence and dignity of the patient, it should constitute the basis of our behaviour as physicians and nurses. Since diagnostic and therapeutic interventions have become more complex and their risk/benefit ratio more difficult to access, the importance of safety and quality of care becomes more and more important. Avoiding the infliction of harm on our patients has become a priority. Patient safety is even viewed as a priority by the Presidency of the European Union. Physicians in intensive care medicine mostly deal with the most fragile and dependent of human beings, frequently at the extremes of age, with multiple co-morbid diseases, and with physiological derangements close to the limits of survival. These patients are often reliant on numerous invasive technologies for their survival. Moreover, the almost universal need for multiple pharmacological interventions, frequently in bundles and associations never scientifically tested before, places the critically ill patients at a very high risk of harm from the physician's interventions. The book is a valuable and useful education tool for physicians and nurses in intensive care medicine. It will help to improve the safety and overall care for critically ill patients.