The epidemiology of genitourinary foreign bodies (GUFB) has been mainly described through case reports and small series. The aim of this study is to investigate the epidemiologic, medical, and socioeconomic factors associated with GUFB, along with the resultant costs of care in emergency departments (EDs) nationwide. ED visits with the primary diagnosis of a GUFB between 2010 and 2014 were abstracted from the Nationwide Emergency Department Sample database. Between 2010 and 2014, a weighted estimate of 102,333 visits to the ED with GUFB were recorded in the US, representing a national incidence of 7.6 ED visits per 100,000 persons. Of these visits, 4.7% resulted in admission and males were more likely to be admitted (24.8% vs. 2.1%, p < 0.01). A third of patients had low income, 30% had no medical insurance, and a third of patients had Medicaid. Urethra/bladder and penile foreign bodies had a significant association with mental health disorders (35.6%). Vulvar/vaginal foreign bodies had a lower prevalence of mental health disorders (6.1%). Costs of managing patients in the ED averaged $3769. More importantly, penile or urethra/bladder foreign bodies incurred a higher cost ($30,071). This is the largest population-based study investigating the epidemiology of GUFB. GUFB are more common in young women and the majority of them are vulvar/vaginal. Urethral and bladder foreign bodies occurred in older male patients and are associated with longer hospital stays and costs. Over one third of male patients with urethra/bladder had significant mental health disorders.