OBJECTIVES: In the United States, more than 628,000 ankle injuries are treated in emergency facilities per year, accounting for 20% of all injury-related emergency department visits. Ankle sprains represent a common injury in emergency departments. We assessed the demographic characteristics, national incidence and burden of ankle sprains in United States emergency departments. We also characterized the most common complications and procedures undertaken for these injuries. METHODS: We conducted a retrospective cross-sectional study using 2010 Nationwide Emergency Department Sample.  Utilizing ICD-9 codes, we identified ankle sprain patients. Propensity score (1:1 nearest neighbor) matching was performed between lateral and medial as well as lateral and high ankle sprains to compare multiple dependent variables (e.g. charges, complications, procedures) among ankle sprain diagnoses. RESULTS: We estimated the incidence of ankle sprains at 1,016,282 cases. The patient mean age was 30.18 years. Females sustained more lateral ankle sprains (57%) than males. After propensity score adjustment, the total charges for lateral sprains were higher than medial sprains [Median (IQR): $1,008 ($702 to $1,408) versus $914 ($741 to $1,108), P < 0.01]. Among complications, pain in the limb (1.92% versus 0.52%, P =0.03), sprain of the foot (2.96% versus 0.70%, P <0.01), and abrasion of hip and leg (1.57% versus 0.35%, P= 0.03) were significantly higher in the lateral group. Among procedures, medial ankle sprain patients were more likely to undergo diagnostic radiology and related techniques than lateral (97.91% versus 83.62%, P <0.0001). High ankle sprains accounted for higher in-patient hospitalization compared to lateral ankle sprains (24 [6.06%] versus 1[0.25%], P<0.0001).  CONCLUSIONS: There are differences in patient characteristics, procedures performed, and charges associated with different ankle sprain types. Demographic risk factors such as age and sex may be useful indicators to identify those at higher risk of sustaining an ankle sprain and more likely to benefit from preventive measures.