Treating children in an intensive care unit aims at the reversal of physiologic derangement of their organism while caring for comfortable physical and psychological environment. Any correctable environmental and physical factors causing discomfort should be addressed before the introduction of effective analgesia and sedation by pharmacological means; a normal schedule for sleep is desirable, and attention should be paid to the provision of feeding and hydration, lighting, environmental noise and the temporal orientation of the patients. All critically ill children have the right to adequate pain relief. Once adequate analgesia has been achieved, additional sedation may be required by some children. The aims of sedation are to reduce anxiety and distress of the child, and to allow for better tolerance of therapeutic and diagnostic procedures. Monitoring the level of analgesia and sedation will help to avoid both over and under treatment. There is no ideal method that will evaluate analgesia and sedation in all critically ill children. Pain scales according to child age should be used routinely, whereas the COMFORT scale is considered to be the most suitable clinical sedation scale for use in critically ill children requiring mechanical ventilation. Rather than seeking an ideal drug, strategies of drug administration that focus attention on principles of sedative pharmacology in critical illness should be utilized, and all sedation techniques must be patient-focused and individualized to patient needs through the utilization of Analgo-Sedation algorithms.