The best one-dimensional method for routine self-assessment of acute pain intensity in a hospital emergency department is unknown. In this study, an 11-point numerical rating scale (NRS), a simple verbal rating scale describing five pain states (VRS), and a visual analogue scale (VAS) were presented successively on admission to 290 patients with acute pain (200 with and 90 without trauma). VAS and NRS were closely correlated for both traumatic (r = .795) and nontraumatic pain (r = .911). The VAS could not be used with 19.5% of patients with trauma and the VRS with 11% of patients without trauma, whereas the NRS could be used with 96% of all patients. The NRS proved more reliable for patients with trauma, giving equivalent results to those with the VAS for patients without trauma. These two scales showed better discriminant power for all patients. Thus, the NRS would appear to be the means for self-evaluation of acute pain intensity in an emergency department.