Incidence of pelvic and acetabular fracture is increasing in Europe. From 2007 to 2014 in the USA, this study found an age-adjusted incidence of 198 and 40 fractures/100,000/year, respectively, much higher than what has been described before. Incidence remained steady over that period and only a small increase in incidence of pelvic fracture in men was identified. PURPOSE: To determine the incidence of pelvic ring and acetabular fractures in the USA over the period 2007-2014 and to examine trends over time. METHODS: Retrospective population-based observational study using data from the Nationwide Emergency Department Sample (NEDS), a 20% stratified all-payer sample of US hospital-based emergency departments (EDs). All patients seen in the ED and diagnosed with pelvic/acetabular fracture from 2007 to 2014 were included. The primary outcome was age-adjusted incidence of pelvic and acetabular fractures per 100,000 persons/years. Secondary outcomes included incidence stratified by age and sex, patient- and hospital-related characteristics, and ED procedures. Tests for linear trends were used to determine if there were statistically significant differences by sex and age groups over time. RESULTS: The age-adjusted incidence of pelvic fracture was 198 fractures/100,000/year, 323 in women and 114 in men. The age-adjusted incidence of acetabular fracture was 40 fractures/100,000/year, 36 in women and 51 in men. A small increase in the age-adjusted incidence of pelvic fracture in men was the only significant trend observed during the study time (p = 0.03). Over that period, the mean age of patients at presentation increased, as well as their number of comorbidities and associated fragility fractures, and they were more often sent home or to nursing facilities. CONCLUSIONS: When considering all patients coming to the ED, not only those admitted to the hospital, adjusted incidence of pelvic and acetabular fracture is much higher than what has been described before. Contrarily to the global increase seen in other countries, incidence of pelvic and acetabular fractures dropped in the USA from 2007 to 2014 and only a small increase in age-adjusted incidence of pelvic fracture in men was identified.