Aim. The authors proposed to retrospectively assess the incidence of ankle sprain and the relevant risk factors in footballers playing in the teams of the province of Parma during a professional season. Methods. Sixty-six football clubs from the province of Parma associated with the Italian Football Federation were contacted. Each athlete involved filled out a questionnaire. Results. Fifty-three athletes out of 1452 had suffered a case of ankle sprain during the professional season; 3.76% of these were amateurs, 2.1% were semi-professionals, and 18.2% were professionals. It was highlighted that in the majority of cases the ankle sprain was caused by contact during the game and that there were significant relations between the distortion and the period of the year, the number of weekly training sessions, the type of footwear worn, the characteristics of the pitch and the presence of past traumas. Discussion. The level of sports activity appears to be an important factor in injury-related risks, the resumption of the professional activity between August and October is related to a higher incidence of traumatisms. A more intense training session seems to protect from traumas, while the incidence of sprain does not appear to be related to the role of the player. Conclusion. There are different causes of ankle sprain in footballers. To reduce the incidence of these traumas it is advisable to apply adequate preventive measures on the basis of the most frequent risk factors.