Thirty-six patients with chronic rotator cuff–related shoulder pain (C-RCRSP) were randomized to receive comprehensive physiotherapy (CP; n=18) or CP plus graded motor imagery (CP+GMI; n=18). The primary outcomes were pain (NPRS) and function (SPADI). Secondary outcomes included pressure pain threshold (PPT), range of motion (ROM), left/right judgment task (LRJT) accuracy and response time, motor imagery ability (VMIQ-2), central sensitization symptoms (CSI), fear-avoidance and catastrophizing (FABQ, PCS), two-point discrimination, and global rating of change (GRC). Pain and PPT were repeatedly assessed at baseline, weeks 1–2, and week 6; other measures were assessed at baseline and 6 weeks. Overall, the results of the study revealed clinically important within-group improvements in both arms for pain, ROM, SPADI, and pain-related fear at 6 weeks, with earlier pain reductions and superior mechanosensory/neurocognitive gains in CP+GMI. In conclusion, adding GMI to physiotherapy appears to accelerate pain relief and enhance mechanical sensitivity and neurocognitive measures, though 6-week endpoint clinical differences vs physiotherapy alone were limited.