Background American Gastroenterological Association guidelines recommend performing EUS to characterize subepithelial lesions (SELs) discovered on upper endoscopy (EGD), followed by surveillance if no high-risk features are identified. However, limited data are available on the impact of and compliance with surveillance recommendations. Objective To determine the natural history of SELs < 30 mm in size evaluated by EUS and to determine the degree of patient compliance with surveillance recommendations. Design Prospective registry. Setting Two tertiary centers. Patients We studied 187 consecutive adult patients referred for EUS evaluation of foregut SELs. Main Outcome Measurements Proportion of patients in whom SELs change in size or echo-features and compliance with follow-up recommendations. Results Surveillance was recommended in 65 patients with hypoechoic SELs (44.6% women, age 59.5 ± 13.2 years); of these, 29 (44.6%) underwent surveillance EUS as recommended and were followed for a median of 30 months (range, 12-105). During follow-up, 16 SELs (25%) increased in size, with a mean increase of 3.4 ± 3.9 mm (range, 1-15). No changes in echo-texture of the SELs were observed. One patient was referred to surgery during follow-up (because of SEL growth > 30 mm). Limitations Short follow-up duration; compliance was a secondary aim. Conclusions During a median follow-up of 30 months, growth in size was observed in 25% of small foregut SELs. However, change in size was minimal, and only 1 patient was referred for surgery based on surveillance EUS findings. Compliance with surveillance recommendations is poor, with fewer than 50% of patients undergoing surveillance EUS as recommended.