Background: Surgical treatment for ureteral orifice-invasive bladder tumors is tricky and remains controversial. Objective: This study compared the efficacy and safety of thulium laser en bloc resection of bladder tumor (ERBT) and transurethral resection of bladder tumor (TURBT) for ureteral orifice-invasive tumors. Methods: Clinical data of patients with non-muscle invasive bladder tumors close to or invading the ureteral orifice from March 2016 to October 2023 were retrospectively analyzed. Pre-operative imaging confirmed no ureteral dilation or hydronephrosis. Bladder instillation chemotherapy was administered based on the pathological findings. Follow-up with cystoscopy and imaging was conducted every 3 months for 1–2 year(s), and then every 6 months thereafter. Results: Forty-two patients were included (25 ERBT, 17 TURBT). All surgeries were completed without intraoperative complications. Median follow-up lasted for 22 months. Baseline median age (65 vs. 63 years, p=0.27), tumor number (all solitary), and size (2.85 ± 1.06 cm vs. 3.14 ± 0.82 cm, p=0.37) were comparable between the TURBT and ERBT groups. Mean operative time was shorter with ERBT (16.08 ± 3.26 min) than with TURBT (30.00 ± 3.53 min; p=0.01). Post-operative hematuria occurred in two TURBT cases and none in ERBT (p=0.006). Detrusor muscle sampling was missed in seven TURBT cases and none with ERBT (p=0.003). Hospitalization was shorter for ERBT (3.12 ± 0.73 days) than with TURBT (4.53 ± 0.80 days; p=0.04). No short-term ureteral stenosis or hydronephrosis developed in either group. Conclusion: ERBT safely resects ureteral orifice-invasive tumors, avoids double-J stenting, and protects the ureteral orifice, rendering it preferable to TURBT in this setting.