Background Adhesive capsulitis is a common cause of glenohumeral joint pain and stiffness that significantly interferes with patients' lives and ability to work. Since no specific treatment options have been well established, this research examines arthrographic injection of the glenohumeral joint with steroid and local anesthetic versus local anesthetic alone for the treatment of adhesive capsulitis. Methods A double-blinded randomized controlled trial was conducted with patients diagnosed with idiopathic adhesive capsulitis. They were randomized to one of two groups: (1)local anesthetic plus steroid or (2)local anesthetic. A musculoskeletal radiologist performed all of the image-guided injections using a standardized patient-blinded technique. Outcome measures included shoulder range of motion, grip strength, and scores on the Shoulder Pain and Disability Index (SPADI), Constant Score, and Visual Analog Scale (VAS) for pain. Evaluations occurred at baseline and 3-, 6- and 12-weeks post-injection. Results Thirty-seven patients were enrolled in the study. There was no significant improvement in shoulder range of motion and grip strength with local anesthetic plus corticosteroid injection compared to local anesthetic alone. Shoulder range of motion was better at all time points for the group with local anesthetic alone. Both groups showed significant improvements in their VAS and SPADI pain scores at all post-injection follow-up appointments (p=.011). The SPADI results showed significantly better disability scores for the local anesthetic plus steroid group (p=.012) and improved pain scores from baseline at all follow-up times (p=.011), whereas the local anesthetic group had significant pain relief for only the first 3 weeks (p=.050). Conclusion Intra-articular injection with local anesthetic plus steroid was beneficial in improving pain but not range of motion when compared to injection with local anesthetic alone.