34 patients with shoulder pain due to tendinopathy were randomized to investigate the effect and safety of interferential light therapy compared to conventional light therapy. Patients were allocated to 10 session over two weeks of either of the aforementioned interventions. Outcomes in pain and disability were measured after the two week intervention period. The results indicated that the interferential light therapy group had reduced pain specifically in abduction and external rotation, although groups did not significant differ for daily pain, nightly pain, and in flexion, extension, and internal rotation. No differences in disability were observed between groups as well.