Abstract Critically ill patients are particularly vulnerable to pain, patient’s citing it as their second greatest ICU stressor. Pain has also been identified as a complicating factor in critical illness. Despite this, pain management is often not considered a priority by the ICU team. Effective management can only be achieved with accurate pain assessment. However, this is difficult in the critically ill as patients are often unable to communicate verbally due to the presence of endotracheal/tracheostomy tubes, sedation and paralysing agents. Nurses therefore rely on behavioural and physiological indicators in establishing the presence of pain. However, as these also occur in situations and conditions not associated with pain there is a need for a systematic, objective assessment tool. Such a tool, consisting of a numerical and verbal rating scale to facilitate documentation and audit, was developed as a result of ongoing adjustment and evaluation. The tool scores the patient’s pain by incorporating behavioural and physiological indicators and is used in conjunction with the Glasgow Coma Score and the modified Sheffield Sedation Scale to achieve a comprehensive neurological assessment. As movement and intervention may exacerbate pain, assessment is carried out at rest and during procedures such as suctioning and manual handling. As an aid to pain assessment and management a flow chart and a clinical guideline have also been introduced. Although preliminary evaluation established the effectiveness of the tool as a means of estimating and recording pain levels in individual patients, it was evident that there has been no change to the way in which pain is managed. To address this issue, the level of nurses understanding regarding pain management has been ascertained and teaching sessions delivered to increase the profile of pain management in the unit.