Sedation is a technique widely used in intensive care unit patients. The main objective is to ensure a proper level of analgesia and the best physical and psychical comfort possible. For the vast majority of patients a light level of sedation is adequate and the level of sedation can easily be deepened to perform a short but painful procedure. A deeper level of sedation, close to that of a general anesthesia is rarely needed and limited to specific indications: adult respiratory distress syndrome, head trauma, status asthmaticus. Drugs used for sedation are combinations of opioids (fentanyl or sufentanil), benzodiazepines (midazolam) and hypnotic drugs such as propofol. In combination with the pharmacological approach, a psychological approach is of greater interest in conscious patients.