ImportanceSurveillance endoscopy is recommended for patients with low-grade intraepithelial neoplasia (LGIN); high-quality evidence about the use of surveillance endoscopy and esophageal squamous cell carcinoma (ESCC) incidence in patients with LGIN is important but limited.ObjectiveTo estimate long-term ESCC incidence rates in patients with LGIN and the association between surveillance endoscopy and ESCC incidence.Design, Setting, and ParticipantsThis community-based, multicenter, prospective cohort study in 9 regions in rural China included patients with LGIN diagnosed by endoscopic screening between July 1, 2007, and December 31, 2016; all participants were followed up until December 31, 2021.Main Outcomes and MeasuresThe primary outcome was ESCC incidence. The ESCC standardized incidence ratio (SIR) was estimated using sex- and age-specific incidence in the general population of rural China in 2010 and hazard ratios (HRs) and 95% CIs were calculated using Cox proportional hazards models.ResultsA total of 3258 patients with LGIN were included; 1772 (54.39%) were men, with a mean (SD) age of 58.21 (6.97) years. Among them, 1378 patients (42.30%) underwent at least 1 surveillance endoscopy (surveillance group) and 1880 (57.70%) did not undergo any surveillance endoscopy (nonsurveillance group). During the follow-up period (median, 7.96 years; IQR, 6.08-10.54 years), 170 ESCC cases were diagnosed, with a cumulative incidence of 6.28 per 1000 person-years. A higher incidence of ESCC (incidence rate, 7.07 per 1000 person-years) was observed in the nonsurveillance group than in the surveillance group (incidence rate, 5.14 per 1000 person-years). Patients with LGIN in the surveillance group had a lower SIR (SIR, 4.07; 95% CI, 1.13-10.34) than those in the nonsurveillance group (SIR, 5.65; 95% CI, 2.00-12.58); however, patients with LGIN in both groups had a higher risk of ESCC than the general population. Patients in the surveillance group had a 31% decreased risk of ESCC incidence (HR, 0.69; 95% CI, 0.50-0.95) compared with those in the nonsurveillance group, after adjusting for baseline risk factors.Conclusions and RelevanceIn this prospective cohort study, patients with LGIN had a higher risk of developing ESCC than the general population, and endoscopic surveillance was associated with a decrease in ESCC incidence in these patients.