Pain is a personal, individual and subjective experience. The complex and dynamic nature of pain makes its assessment and management challenging for healthcare professionals. Various pain scales are available that can assist in identifying the patient’s experience of pain; however, these tend to reduce this experience to a measure of pain intensity. The use of pain scales also requires patients to communicate and describe their pain; when this is not possible, it is necessary for healthcare professionals to observe patient behaviours that may indicate pain. Various observational pain assessment tools have been developed to assist in recognising and assessing pain. This article discusses the various pain scales and observational pain assessment tools that are available, and the evidence to support their use.