Appropriate use of diagnostic and treatment modalities are essential for rational use of resources. The aim of this study is to evaluate the use of diagnostic modalities and different treatment options and their economic impacts following an acute ankle distortion resulting from an occupational accident. We evaluated the type-of-treatment impact on the victims' course of recovery as well as its impact on the associated accident costs. Research was carried out in Belgium. An ankle distortion victims' database consisting of 200 cases of (Belgian) occupational accidents during the period 2005-2007 was analysed. Patients who were prescribed immobilization or the use of adjuvant support or physical therapy (118 cases) were not employed during a period of 37 days on average, with a mean total cost of 3140.14 Euros caused by the ankle sprain. Patients without any adjuvant therapy (82 cases) were characterized by an unemployment rate of 15 days on average, and a total cost of 1077.86 Euros. Cast immobilization, although its application is not supported by evidence-based literature, was still applied in 36% of the population studied and resulted in the longest average absence of work of 42 days with an obvious significant increase in medical and total costs. Our results show a high rate of inappropriate use of cast immobilizations for ankle distortions. From an economic point of view and for the same clinical endpoint (being full resumption of the occupational activities), simple conventional treatment, consisting of rest, ice, compression and elevation at diagnosis with allowance of early weight bearing in the further clinical course, leads to the quickest full resumption of activities in combination with the lowest medical costs, if compared with any other kind of treatment.