The aim of this study is to evaluate the results of routine and selective postoperative upper gastrointestinal series (UGIS) after Roux-en-Y gastric bypass (RYGB) for morbid obesity in different published series to assessing its utility and cost-effectiveness. A search in PubMed's MEDLINE was performed for English-spoken articles published from January 2002 to December 2012. Keywords used were upper GI series, RYGB, and obesity. Only cases of anastomotic leaks were considered. A total of 22 studies have been evaluated, 15 recommended a selective use of postoperative UGIS. No differences in leakage detection or in clinical benefit between routine and selective approaches were found. Tachycardia and respiratory distress represent the best criteria to perform UGIS for early diagnosis of anastomotic leak after a RYGB.