OBJECTIVE Acute abdominal pain is a prevalent problem in the emergency department. The work-up has to include a broad spectrum of differential diagnoses, which should be narrowed down with respect to frequent diagnoses without overlooking rare but potentially even more severe pathologies. METHODS The radiological method of choice for the initial work-up after sonography is computed tomography, which has demonstrated the highest sensitivity and specificity for most findings. Plain film radiographs of the abdomen rarely contribute to the final diagnosis. Magnetic resonance imaging is reserved for selected cases, which are described in this article. RESULTS The clinical decision trees and recommendations, which need to be in the report depending on the diagnosis, are of relevance for every radiologist who deals with patients with acute abdominal presentations. CONCLUSIONS Knowledge of the clinical diagnostic approach in patients with acute abdomen is an unavoidable prerequisite for optimal cooperation between clinicians and radiologists in acute situations.