This retrospective study aimed to compare the short- and long-term outcomes of endoscopic submucosal dissection and laparoscopic and endoscopic cooperative surgery in patients with superficial non-ampullary duodenal epithelial tumors. We investigated consecutive patients with SNADETs > 10mm in size who underwent ESD (ESD group) or LECS (LECS group) between January 2015 and March 2021. The data was used to analyze the clinical course, management, survival status, and recurrence between the two groups. A total of 113 patients (100 and 13 in the ESD and LECS groups, respectively) were investigated. The rates of en bloc resection and curative resection were 100% vs. 100% and 93.0% vs. 77.0% in the ESD and LECS groups, respectively, with no significant difference. The ESD group had shorter resection and suturing times than the LECS group, but there were no significant difference after propensity score matching. There were also no differences in the rates of postoperative adverse event (7.0% vs. 23.1%; P = 0.161). The 3-year overall survival (OS) rate was high in both the ESD and LECS groups (97.6% vs. 100%; P = 0.334). One patient in the ESD group experienced recurrence due to liver metastasis; however, no deaths related to SNADETs were observed. ESD and LECS are both acceptable treatments for SNADETs in terms of a high OS rate and a low long-term recurrence rate, thereby achieving a comparable high rate of curative resection. Further studies are necessary to compare the outcomes of ESD and LECS for SNADETs once both techniques are developed further.