Background/Aims: The efficacy of anti-tumor necrosis factor α (anti-TNFα) antibodies for postoperative Crohn's disease (CD) in patients who were treated with these agents prior to surgery is largely unknown. Methods: CD patients who underwent intestinal resection and received anti-TNFα agents after surgery were divided into 2 groups according to the presence or absence of preoperative anti-TNFα treatment: anti-TNFα restart group or anti-TNFα naïve group. Endoscopic recurrence after surgery was examined according to the preoperative conditions, including administration of anti-TNFα agents before surgery. Results: Thirty-six patients received anti-TNFα antibody after surgery: 22 in the anti-TNFα restart group and 14 in the anti-TNFα naïve group. Endoscopic recurrence after surgery was more frequently observed in the anti-TNFα restart group than in the anti-TNFα naïve group (68% vs. 14%, P<0.001). Multivariate analysis revealed the following significant risk factors of endoscopic recurrence after surgery: anti-TNF restart group (odds ratio [OR], 28.10; 95% CI, 3.08-722.00), age at diagnosis <23 years (OR, 24.30; 95% CI, 1.67-1,312.00), serum albumin concentration at surgery <3.3 g/dL (OR, 34.10; 95% CI, 1.72-2,804.00), and presence of inflammation outside of the surgical site (OR, 21.40; 95% CI, 1.02-2,150.00). Treatment intensification for patients with endoscopic recurrence in the anti-TNFα restart group showed limited responses, with only 1 of 12 patients achieving endoscopic remission. Conclusions: The efficacy of restarting anti-TNFα antibody treatment after surgery was limited, and treatment intensification or a change to different classes of biologics should be considered for those patients.