This work was aimed at investigating the CT anatomy in patients submitted to Nissen's fundoplication. Forty patients (mean age: 61 years) with peptic esophagitis (9 patients), refractory gastroesophageal (GE) reflux (11 patients) and hiatal hernia (20 patients) were examined. CT studies were performed with a third generation unit (CT Pace, General Electric, USA) with the patients in the prone position, after Gastrovison (Schering) and barium paste administration. In 34 patients, CT demonstrated surgery-related anatomical changes, such as the presence of a soft tissue mass at the distal third of the esophagus. In 4 patients, functional incompetence of the fundoplication (3 patients) and a recurrent hyatal hernia (1 patient) were demonstrated. In conclusion, CT studies performed with a dedicated technique permitted the accurate assessment of the anatomy of the GE junction after Nissen's fundoplication. In our study, CT demonstrated the presence of postoperative fluid collections and specific signs related to fundoplication incompetence. Our results suggest a possible application of CT to the postoperative follow-up of the patients submitted to Nissen's fundoplication, with a complementary role that of to endoscopy and functional exams.