The authors' objective was to describe a method for measuring interobserver agreement and to determine the reliability of physical findings used by emergency physicians to assess ankle injury patients. A 3-month prospective survey was designed for use in the emergency departments of two university hospitals. Participants were a convenience sample of 100 adult blunt ankle injury patients. Pairs of emergency staff physicians assessed 22 standardized physical findings in each patient without knowledge of the other assessment. Agreement for each variable was measured by the kappa coefficient, the ratio of actual agreement to potential agreement beyond chance. The variables with the highest interobserver agreement and their kappa values were ability to bear weight (.83); bone tenderness at the base of the fifth metatarsal (.78), at the posterior edge of lateral malleolus (.75), and at the tip of the medial malleolus (.66); and combinations of bone tenderness (.76). Less reliable variables included soft tissue tenderness (.41) or degree of swelling (.18) of the anterior talofibular ligament, ecchymosis (.39), range of motion (.33), bone tenderness at the proximal fibula (-.01), and the anterior drawer sign (-.03). High kappa values indicate that several physical findings, including ability to bear weight and selected sites of bone tenderness, may be reliably assessed in ankle injury patients. This knowledge may give physicians more confidence in their physical examination and allow development of reliable clinical guidelines to diminish the reliance on radiography in ankle injuries.