ObjectiveTo compare perineural dextrose injection efficacy in the treatment of ulnar neuropathy at the elbow with a control group. DesignProspective double-blind randomized control study. SettingTraining and research hospital. ParticipantsThe study was completed with 40 patients with ulnar neuropathy at the elbow. InterventionNormal saline (0.9% sodium chloride) was injected in patients in the control group (n=20; mean age=38.1±10.7 years; median duration of symptoms=4.5 months), and 5% dextrose was injected in patients in the dextrose group (n=20; mean age=43.6±13.5 years; median duration of symptoms=5 months), perineurally under ultrasound guidance twice at 2-week intervals. Ultrasound-guided perineural injection of 1 cc each was administered into the ulnar nerve, 2 cm and 4 cm distal to the medial epicondyle, at the level of the medial epicondyle, and 2 cm and 4 cm proximal to the medial epicondyle. The amount of total fluid injected was 5 cc. Main Outcome Measure(s)At baseline and weeks 2, 4, and 12, the patients were evaluated with the Visual Analog Scale for pain and the Disabilities of the Arm Shoulder and Hand questionnaire for disability. Electrophysiological evaluation was performed with ulnar nerve conduction studies, and the ulnar nerve cross-sectional area was measured on ultrasonography. ResultsThe improvements in pain, disability, ulnar motor nerve velocity, and ulnar nerve cross-sectional area in the dextrose group were superior to those in the control group, especially at weeks 4 and 12 (P<.001, using independent samples t tests). ConclusionPerineural 5% dextrose may be an effective alternative therapy for those with ulnar neuropathy at the elbow for up to the 12th week.