When should a patient with abdominal pain be referred to the emergency ward? The following goals must be achieved upon managing patients with acute abdominal pain: 1) identify vital emergency situations; 2) detect surgical conditions that require emergency referral without further diagnostic procedures; 3) in "non surgical acute abdomen patients" perform appropriate diagnostic procedures, or in selected cases delay tests and reevaluate the patient after an observation period, after which a referral decision is made. Clues from the history and physical examination are critical to perform this evaluation. A good knowledge of the most frequent acute abdominal conditions, and identifying potential severity criteria allow an appropriate management and decision about emergency referral.