Background: Transurethral resection of recurrent low-grade intermediate-risk Ta bladder tumor (BT) in general anesthesia (GA) is burdensome to patients and health care system. Laser technologies enable treatment in office-based settings, reducing morbidity and costs. Objective: To compare 4-mo recurrence-free survival after outpatient department (OPD) diode laser coagulation of BT in local anesthesia and gold standard transurethral resection of BT (TUR-BT) in GA in intermediate-risk Ta low-grade BT, and to evaluate treatment-related morbidity. Design, setting, and participants: A prospective randomized noninferiority trial with 4-mo follow-up, in the hospital setting, was conducted in Capital Region of Denmark from 2016 to 2020. Participants were patients with histologically verified Ta low-grade BT recurrence. A total of 206 patients were randomized; 176 finished treatment and follow-up as per protocol. Intervention: Laser photocoagulation of bladder tumor (PC-BT) in OPD using a 980 nm diode laser compared with gold standard TUR-BT in GA, both performed with photodynamic diagnosis (PDD) guidance. Outcome measurements and statistical analysis: Four-month recurrence-free survival was assessed; predefined inferiority criterion was set at 15%. The secondary outcomes were pain during PC-BT, postoperative morbidity, postoperative complications, and patient's preference. Results and limitations: Four-month recurrence-free survival was 8% higher after PC-BT (95% confidence interval [CI]: –8% to 24%). The predefined noninferiority criterion was met. Pain score (1–10) during PC-BT was 2.4 (interquartile range 0.8–3.3). Postoperative lower urinary tract symptom score (0–100) was 13.9 points higher (95% CI: 6.9–21.0, p < 0.001) in the group with transurethral resection of the bladder. The frequency of minor complications was 8.1% higher after TUR-BT (95% CI: 1.0–14.6%, p = 0.026). Of the patients, 98% (95% CI: 92–100%) preferred PC-BT. Conclusions: PDD-guided PC-BT in OPD is as good as TUR-BT in GA to remove recurrent low-grade Ta BT. Postoperative quality of life is better after PC-BT and the frequency of minor complications was lower. Patient summary: This study evaluates the efficacy of outpatient laser removal of low-grade noninvasive bladder tumor. Outpatient tumor removal with laser was as good as transurethral resection in general anesthesia and less burdensome to patients.