Acute abdominal pain is one of the most commonly encountered leading symptoms in the emergency department. Although it is oftentimes held for a purely surgical problem, two thirds of patients do not require operative management. The causative pathologies of the acute abdomen range from intra-abdominal to extra-abdominal and metabolic diseases. Therefore a multidisciplinary approach is imperative and early consultation is key in order not to unnecessarily delay treatment. Clinical experience is equally as important as a sound knowledge of the anatomy and physiology of the abdominal cavity and an understanding of the pathophysiological processes at work. This knowledge should be applied whilst taking a history and performing the physical examination. Investigative studies are indispensable in the evaluation of the acute abdomen, especially since at least one third of patients presents with atypical features. Thereby the age of the patient plays an important role. Elderly patients may present with signs and symptoms unimpressive to the untrained eye, yet harbouring a serious pathology. Laboratory tests by themselves are not enough to assess the patient, so radiological studies have to be a deeply rooted part of the patient evaluation. With ultrasonography, plain abdominal films, computed tomography, CT-angiography and magnetic resonance imaging a broad array of imaging modalities, are at the ED physician’s disposal. In choosing a modality the diagnostic yield of such a procedure should be weighed against the risk of radiation exposure. The severity of aetiologies ranges from benign self-limiting to life-threatening. Hence the main focus of the ED physician should be to triage the patient accordingly and discern whether immediate or urgent surgical intervention is necessary. Thereby a priority- and problem oriented strategy should be pursued. In order to prevent diagnostic errors and improve patient care, diagnostic algorithms and patient evaluation forms should be used.