To analyze visits to and admissions from the emergency department (ED) in children with a primary diagnosis of functional abdominal pain (FAP). This was a cross-sectional study using data from the Nationwide Emergency Department Sample (HCUP-NEDS 2008–2012). FAP-related ED visits were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes. The most frequent secondary diagnoses associated with FAP-related ED visits were also extracted. In 2012, a total of 796,665 children presented to the ED with a primary diagnosis of FAP. This correlated to a rate of 11.5 ED visits/1000 population. The highest incidence of ED visits was observed for children in the 10–14-year age group; median (IQR) age of 11 (8) years. In analyzing the temporal trends associated with FAP-related ED visits, we observed an increase in both the overall number of visits (14.0%) as well as the population-adjusted incidence (16.0%) during the period 2008–2012. This coincided with a decreasing trend in hospital admissions from the ED; from 1.4% in 2008 to 1.0% in 2012 (−28.5%). The overwhelming majority (96.7%) of patients with FAP who presented to the ED were treated and released. On multivariate analysis, the leading factor associated with an increased likelihood of admission from the ED was teaching hospital status (aOR 2.07; 95% CI 1.97 to 2.18). The secondary diagnosis most commonly associated with FAP-related ED visits was nausea and/or emesis (19.8%). Pediatric FAP-related ED visits increased significantly from the period 2008 to 2012. However, the incidence of hospital admissions from the ED declined during the same period.