Pain assessment and control should he a priority within nursing but pain is often underassessed and unrelieved. Pain is difficult to assess as it is complex and subjective, and assessment is influenced by many factors. A pain assessment tool can he invaluable as it can aid the patient to communicate his or her pain. remove the subjectivity of assessment, and promote a systematic approach. A variety of pain assessment tools have been developed and used in clinical settings with subsequent improvements in assessment. They each have specific attributes, and their place in clinical practice is considered. It is concluded that the use of pain assessment tools is advantageous, and the reasons why they are not used more widely are considered