Abdominal pain is a frequent symptom in Emergency Departments. Often is not so easy make a diagnosis of cause. Particular importance in young women has differential diagnosis with gynecological diseases. Often laboratory exams have not good specificity. US and TC are the imaging techniques most used to make a diagnosis, but both have ours limits. Definitely surgeon's experience is the most important resource for a correct approach to abdominal pain. We present two cases of low abdominal pain in young women due to ovarian teratoma erroneously diagnosed as appendicitis.