Aim: We aimed to evaluate the effects of laser therapy together with rest splint and exercise on muscle strength, function, activities of daily living, and pain in individuals suffering from cubital tunnel syndrome (CuTS) by comparing it with placebo treatment. Materials and Methods: This prospective, single-blind, and randomized controlled study was conducted with 64 patients with CuTS in total. They were divided into two groups by randomization: Group 1 (n = 32) was provided with low-energy laser therapy + splint + exercise, and Group 2 (n = 32) was provided with low-energy sham laser therapy + splint + exercise. Patients in both groups received resting splints and nerve release exercises. Pretreatment and posttreatment (3rd week, 3rd month) evaluations were made with the Visual Analog Scale (VAS), the Quick Disability of Arm, Shoulder, and Hand Questionnaire, hand grip strength, fingertip grip strength, the Patient-Rated Ulnar Nerve Evaluation Scale (PRUNES), and Short Form-12. An electrophysiological evaluation was performed at baseline and at the 3rd month. Results: We observed significant improvements in both groups regarding pain, function, muscle strength, health profile, and quality of life in the early posttreatment (3rd week) stage and at the 3rd-month follow-up. When both groups were compared, a significant difference was determined between the VAS-Rest, VAS-Movement, PRUNES-Pain, PRUNES-Function, and PRUNES-Total parameters in the posttreatment (3rd week follow-ups), as well as PRUNES-Pain scores in the post-treatment (3rd month) stage, of the groups in favor of those in Group 1 (p < 0.05). Conclusion: The findings of our study have shown that in the treatment of CuTS, laser treatment is superior to placebo in the short term, but they have equivalent effects in the medium term. Further studies with large patient populations are needed to provide more diverse information about the therapeutic effectiveness of low-intensity laser therapy.