Background: Frozen shoulder (FS) is a highly disabling pathology of poorly understood etiology, which is characterized by the presence of intense pain and progressive loss of range of motion. The aim of this study was to evaluate the effect of adding a central nervous system (CNS)-focused approach to a manual therapy and home stretching program in people with FS. Methods: A total of 34 patients with a diagnosis of primary FS were randomly allocated to receive a 12-week manual therapy and home stretching program or manual therapy and home stretching program plus a CNS-focused approach including graded motor imagery and sensory discrimination training. The Shoulder Pain and Disability Index score, self-perceived shoulder pain (visual analog scale score), shoulder range of motion, and the Patient-Specific Functional Scale score were measured at baseline, after a 2-week washout period just before starting treatment, after treatment, and at 3 months' follow-up. Results: No significant between-group differences in any outcome were found either after treatment or at 3 months' follow-up. Conclusion: A CNS-focused approach provided no additional benefit to a manual therapy and home stretching program in terms of shoulder pain and function in people with FS.