Abdominal pain is a common complaint in the emergency department (ED), comprising approximately 5% of total visits. Although not typically serious, abdominal pain often presents many difficult situations for the clinician. Women of reproductive age and elderly individuals represent some of the most challenging patients to evaluate. Although there are general diagnostic and clinical principles that apply to the evaluation of all patients, these two groups deserve extra attention because of the broad differential diagnosis and potential for serious complications. This article outlines the epidemiology of abdominal pain in patients who present to the ED, and provides guidelines pertinent to the evaluation of all patients. In addition, the article discusses the approach to abdominal pain of pelvic origin in women of reproductive age and abdominal pain in elderly individuals.