BACKGROUND Ankle fractures are common, and their incidence has been increasing. Previous epidemiological studies have been conducted in the US, Scandinavia, and Scotland. Our objectives were to provide a current epidemiological overview of operatively treated ankle fractures and to evaluate the influence of age, sex, lifestyle factors, and comorbidities on fracture types. METHODS We performed a population-based epidemiological study of all ankle fractures treated operatively in a 10- year period from 2002 to 2012. RESULTS Two thousand forty-five ankle fractures were operated upon. Men and women differed significantly in age (median 41 vs. 57 years old), obesity (16% vs. 23%), diabetes (5% vs. 10%), smoking (45% vs. 24%), and accident type (daily activities 48% vs. 79%, transportation 24% vs. 9%, sports 21% vs. 8%) respectively. Overall, there were 2% Weber A, 77% Weber B, and 21% Weber C fractures; 54% were uni-, 25% bi-, and 21% trimalleolar; 7.5% of all fractures were open. Weber C fractures were much more frequent among men and with higher BMI (lowest vs. highest category: 14% vs. 32%), but slightly less frequent with older age and among current smokers. Trimalleolar fractures were twice as frequent in women and increased with age. CONCLUSIONS Men and women differed substantially in age, lifestyle factors, comorbidities, accident type, and type of ankle fracture. Male sex and higher BMI were more frequently associated with Weber C fractures, whereas female sex and older age were associated with trimalleolar fracture. The risk for severe fracture increased linearly with the degree of obesity.