Objective To determine the prevalence of ankle sprains and its associated factors in athletes. Methods This was a cross sectional descriptive study conducted among a random sample of 107 athletes. The subjects were recruited from 6 different associations in Sousse, Tunisia. Demographic, medical and foot characteristics were collected using a medical file completed by a validated, self administered questionnaire to verify ankle instability. All components of this study were approved by a research ethic committee, and all participants gave informed consent at every stage. Data entry and analysis were performed using SPSS 20 Software. The level of significance was set at p <0.05. ResultsThe prevalence of ankle sprain was 71%. The associated factors were; the weight (p=0.033), the type of sport (p=0.038), the profile of the athlete (p=0.006), the unipodal static balance (p= 0.006), the limitation of the joint mobility (p=10-6), the ligament laxity (p<0.05), the muscular force especially the eversor muscle (the long fibular) (p<0.05) and the inversor muscle (the posterior tibial) (p<0.05) and the ankle instability (p<0.05). Conclusion Ankle sprains remain a frequent trauma in Tunisia. This injury must be taken into consideration and treated with a multidisciplinary approach (physicians, podiatrists, physiotherapists and physical trainers...) in order to lower its occurrence.