Acute intermittent porphyria (AIP) is an inherited disorder of heme metabolism. It can produce a variety of symptoms including abdominal pain. In Spain it is an uncommon disease and consequently may not be included in the differential diagnosis of acute abdominal pain. Two cases of AIP are reported, both of which started with recurrent abdominal pain. A brief commentary of the main topics of the disease is made with special emphasis on the importance of an early diagnosis.