Background:the aim of this study is to evaluate the prevalence and effect of depression and anxiety on the shoulder range of motion, as well as the objective and subjective symptoms in patients suffering from frozen shoulder.Methods:Between 2013 and 2014, in a cross-sectional study, we evaluated 120 patients with idiopathic frozen shoulder. We collected the demographic data for each patient and measured shoulder range of motion in four directions in both limbs. All patients filled out visual analog scale (VAS) for pain and the disabilities of the arm, shoulder, and hand (DASH) questionnaires. Both Hamilton anxiety and depression questionnaires were filled out for each patient.Results:A total of 92 patients (77%) with idiopathic frozen shoulder showed symptoms of depression, while only 32 (27%) of them experienced anxiety. Thirty-two patients (27%) showed symptoms of both depression and anxiety. Although elevation and abduction were not affected by depression, internal and external rotations were more restricted among patients who had symptoms of depression. DASH and VAS scores were higher in patients with symptoms of depression. In terms of anxiety, only VAS and DASH were different between two groups. In multivariable analysis, DASH score was correlated with severity of both anxiety and depression symptoms.Conclusion:While there is no definitive relationship between symptoms of depression or anxiety and shoulder range of motion in patients suffering from frozen shoulder, patients who suffer from depression or anxiety experienced increased pain and limb disability.