The authors report a case of acute abdomen in the third trimester of pregnancy as observed at the II Obstetrics and Gynecologic Department of Florence University. Emphasis is laid on the frequent abnormality of the symptomatology and therefore the difficult of early diagnosis. The conclusion is reached that a greater semeiologic accuracy on behalf of the specialist as well as memorization of the several clinical charts responsible for such pathology, allow an earlier diagnosis with consequent improvement of maternal and fetal prognosis.