[Purpose] To evaluate treatments with interferential current, hot pack, ultrasound therapy, stretching, strengthening and range-of-motion exercises, comparing between the right and left shoulders in terms of pain and functional capacity in patients with frozen shoulder. This was a retrospective study. [Subjects and Methods] Sixty-four patients (34 right side, 30 left side) were treated with interferential current and hot pack application for 20 min each, ultrasound therapy for 3 min, regular range-of-motion exercises, stretching exercises, strengthening with a Theraband in all directions and post-exercise proprioceptive neuromuscular facilitation techniques. All cases were evaluated with visual analogue scales for pain, passive and active range of motion, Constant score, and the shoulder disability questionnaire, at baseline and 7 and 12 weeks after baseline. [Results] Marked improvement was noted in all patients in both right and left sides after treatment, and at 7 and 12 weeks of follow-up compared with baseline. There was no significant difference between the right and left shoulder groups, in all outcome measures. [Conclusion] The combination of physical therapy, exercise, and manual techniques is effective in treating frozen shoulder. The location of the lesion in the right or left shoulder does not, in itself, affect the prognosis or treatment outcome.