The quality and quantity of sedation needs to be titrated in all ICU patients receiving sedation, as given in the recent 2013 Pain Agitation and Delirium (PAD) guidelines, published by the Society of Critical Care Medicine (SCCM). In general, a sedation assessment tool measures the patient’s response to verbal or physical stimuli to various degrees of agitation. An ideal sedation assessment tool would meet the following requirements—easy to score, requiring minimal training, scores both agitation and sedation, good reliability and validity, should be applicable to a wide range of patient population, and have well-defined sedation targets. There are both subjective and objection sedation assessment tools. The RASS and SAS are the most valid and reliable sedation tools. The objective sedation tools can be used on patients to assess the depth of anesthesia in the OR. But their use in ICU on critically ill patients is still not validated.