Pain assessment plays an integral role in the ongoing efforts to improve overall pain management in the acute care setting. This chapter overviews the pain assessment process and outlines some pain rating tools that have been useful in the acute care setting. Some form of explicit pain assessment is necessary, since studies in myriad patient populations have failed to identify consistently reliable surrogate markers for pain. Despite pitfalls in self-reported pain scores, it is important for the objective pain rating to come from the patient. In clinical practice, the most commonly used rating scale is the verbal numeric rating scale. The advantages of the verbal numeric rating scale include ease of administration and high agreement with the visual analog scales used in most clinical pain management studies in acute care. In older adults who are cognitively intact, numerical rating scales or simple verbal reports of pain categories are preferred.