Ankle sprain is one of the most common injuries treated in emergency departments (ED). In clinical practice, these injuries are expected to heal by themselves, often without any treatment other than short information about the RICE regime (rest, ice, compression and elevation). Still, remaining symptoms are reported to occur in 30% of the cases. The aim of this study was to evaluate the effect of early physiotherapy intervention after an acute ankle sprain. Sixty-five patients were recruited from the ED at a general hospital in Sweden (mean age 35 years; 30 women), and allocated into an intervention group with early physiotherapy or a control group. Both groups were evaluated 6 weeks and 3 months after their injury. As primary outcome, the disease-specific Foot and Ankle Outcome Score (FAOS) was used. The patients also rated their physical activity ability and how satisfied they were with their ankle on a visual analogue scale (VAS). The intervention group made significant improvements compared with the control group at both evaluations measured with FAOS and the VAS questions. These findings indicate that early physiotherapy intervention has a positive effect on patient-focused foot and ankle function after an acute ankle sprain. © 2010 Informa UK Ltd.