ObjectivesDelayed bleeding is a rare but important major adverse event (mAE) after endoscopic submucosal tunneling procedures (ESTP), which is scarcely reported. We aimed to characterize the clinical characteristics of delayed bleeding and provide better management of this mAE.MethodFrom August 2010 to October 2022, we reviewed 3852 patients with achalasia receiving peroral endoscopic myotomy (POEM) and 1937 patients with upper gastrointestinal tumors receiving submucosal tunneling endoscopic resection (STER). Among these, records of 22 patients (15 POEM, 7 STER) with delayed bleeding were collected. Clinical characteristics, treatment, and outcomes of delayed bleeding were analyzed.ResultsThe mean age was 43.6 years. Ten patients (45.5%) were intratunnel bleeding, seven (31.8%) were intratunnel bleeding accompanied by mucosal bleeding, and five (22.7%) were mucosal bleeding. The most common accompanied symptoms were hematemesis, fever, and melena. The most common accompanied mAEs were fistula, pulmonary inflammation, and pleural effusion with atelectasis. The mean duration from ESTP to endoscopic intervention was 5.3 ± 4.9 days. Active bleeding was identified in 21 patients (95.5%). The bleeding was successfully controlled by electrocoagulation (19 cases), endoscopic clipping (six cases), and Sengstaken–Blakemore tube insertion (three cases), and no patient required surgical intervention. The mean hemostatic procedure duration was 61.8 ± 45.8 min. The mean post‐bleeding hospital stay was 10.0 ± 6.2 days. A brief meta‐analysis of previous studies showed the pooled estimate delayed bleeding rate after POEM, STER, and G‐POEM was 0.4%.ConclusionsDelayed bleeding is uncommon and could be effectively managed by timely emergency endoscopic procedures without requiring subsequent surgical interventions.