Background: Laparoscopic sleeve gastrectomy (SG) is a well-tolerated and effective procedure for sustained weight loss and amelioration of weight-related co-morbidities. Rarely, unexpected pathology may be identified intraoperatively, which may alter the surgical plan. Gastrointestinal stromal tumors (GISTs) are among the more frequently encountered tumors and pose a particular concern because of their malignant potential. We review our findings of incidental tumors encountered during 1415 consecutive SGs., Methods: Abnormal pathology records from all patients who underwent SG at our institution between 2009 and 2014 were reviewed. Patient demographic characteristics and clinical characteristics, tumor characteristics, including immunohistochemistry, operative course, and patient follow-up were reviewed., Results: There were 17 incidental gastric mesenchymal tumors identified (1.2%) in 1415 SG procedures. This included 12 GISTs (.8%), 2 schwannomas (.1%), and 3 leiomyomas (.3%). In the majority of cases (1210/1415), the gastric specimens were not reviewed by a pathologist because there were no gross abnormalities appreciated by the surgeon. The GISTs were between .3 and 2.9 cm, and all were low grade with negative margins. Patients with GISTs tended to be older (mean age 55±9.3 y) than the rest of the patients. There was no evidence of recurrence on follow-up., Conclusion: Incidental gastric mesenchymal tumors are rarely encountered during SG. The vast majority were GISTs with an incidence of .8% in this population. Concomitant SG and tumor resection were feasible, without compromising the objectives of each. Complete tumor excision is necessary for tumors>2 cm., (Copyright © 2015 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)