To assess the 1-year outcome of standard medical care of acute ankle sprains in a general clinic-based population. A self-administered survey was mailed to all adult patients who presented to a health system provider for evaluation of ankle sprain. A regional primary care health system. Four hundred sixty-seven (66.5%) of 702 patients with ankle sprains evaluated by a system physician from April 1, 1995, to March 31, 1996. Prevalence and severity of self-reported ankle pain, swelling, perceived instability, and perceived weakness 6 to 18 months after medical evaluation. Most patients sought medical evaluation shortly after injury and were immobilized or braced; 32.7% reported formal or home-based physical therapy. Six to 18 months after injury, 72.6% reported residual symptoms. Of these, 40.4% reported at least 1 moderate to severe symptom, most commonly perceived ankle weakness; 40.3% were unable to walk 1 mile; and 43.3% were unable to jump or pivot on the ankle without symptoms. Factors associated with moderate to severe residual symptoms were reinjury of the ankle (odds ratio [OR], 7.21; 95% confidence interval [CI], 4.14-12.68), activity restriction longer than 1 week (OR, 2.04; 95% CI, 1.25-3.32), and limited weight bearing longer than 28 days (OR, 2.16; 95% CI, 1.28-3.63). Residual lifestyle-limiting symptoms are common 6 to 18 months after an ankle sprain. Ankle sprains may be more problematic than generally thought, or standard medical treatment may be inadequate. Further studies evaluating treatment regimens are needed to identify effective methods to reduce the long-term functional limitations of ankle sprain in general clinic populations.