Background: It is not clear whether rehabilitation after surgery for trigger finger is effective. The aim of this study was to reveal the effectiveness for trigger finger. Methods: This study was a randomized, controlled trial that included patients who underwent operations for trigger fingers. The patients in the rehabilitation group had postoperative occupational therapy (OT) for 3 months, while the patients in the control group were not referred for rehabilitation but received advice for a range of motion exercise. We evaluated the severity of trigger finger, Disability of Arm-Shoulder-Hand (DASH) score, pain-visual analogue scale (VAS), grip strength, whether they gained a full range of motion (ROM), and complications before and after surgery. Results: Finally, 29 and 28 patients were included in the control and rehabilitation groups, respectively. DASH score, grip strength, and ROM were significantly improved in the rehabilitation group from that preoperatively at final follow-up. Pain was significantly improved in both groups from that preoperatively at final follow-up. Subgroup analysis showed that there is a significant difference in the DASH score of patients doing housework or light work and those with a duration of symptoms > 12 months between the control and rehabilitation groups at the final follow-up.