BACKGROUND Endoscopic treatment of precancerous lesions and early gastric cancer has been widely accepted in recent years. Endoscopic submucosal dissection (ESD), following established indication criteria, can lead to cure of the disease in more than 90% of cases. OBJECTIVE This study aimed to analyze the use of ESD in patients with early gastric cancer and precancerous lesions, as well as the results of the procedure, its complications and effectiveness in controlling the disease. METHODS This is a retrospective cohort study composed of 41 patients aged from 53 to 87 years (mean age: 65 years; 58.53% male) who were analyzed from 2008 to 2019. The variables collected from the medical records were: comorbidities, classification of the lesion regarding resection criteria, type of resection, histology, degree of invasion, resection margin, complications, disease recurrence. Statistical analysis was performed using the Kruskal-Wallis test, the McNemar's test, and the Mann-Whitney test, with 5% statistical significance (P<0.05). RESULTS The most frequent site of the lesion was the gastric antrum and the predominant presentation by the Japanese or Paris classification was the one with depressed components in 56.09%. Adenocarcinoma occurred in 75.6% of the biopsies, and the remainder were adenomas without neoplasia. En-bloc resection occurred in 97.57% of cases, and compromise of the safety margin occurred in one patient. The main pre-existing comorbidity was liver cirrhosis in 29.26% of cases. There was a significant increase in post- ESD adenocarcinoma compared to pre-resection diagnosis. The mean follow-up time was 38.4 months, with one recurrence (2.43%) and two metachronous lesions (4.87%). Complications during and after the procedure occurred in three patients (7.31%), being due to bleeding (two cases) and perforation (one case). There was one death due to a cardiac event not directly related to the procedure. CONCLUSIONS Endoscopic submucosal dissection proved to be a safe procedure, with a low complication and recurrence rate. Its recommendation must occur within the established criteria; however, it can be indicated for patients outside the criteria, if there is a high risk for surgical treatment.