Camptocormia is an abnormal flexion of the thoracolumbar spine during standing and walking that abates in the recumbent position. In a single-centre epidemiological and clinical study, the prevalence of camptocormia in Parkinson disease (PD) and its relationship with the clinical features of PD were investigated. A total of 275 consecutive outpatients were systematically screened for camptocormia with a clinical evaluation. Patients who screened positive for camptocormia were subsequently reassessed by formal goniometric analysis. The demographic and clinical features of the patients with and without camptocormia were then compared. A 6.9% (19/275, 95% CI, 4.2 to 10.6) prevalence of camptocormia was found. Camptocormia was found in patients with more severe PD, as clinically assessed by the Hoehn-Yahr (HY) staging and the motor Unified Parkinson Disease Rating Scale (UPDRS) part III, longer l-dopa treatment duration and greater l-dopa daily dose and presence of DSM-IV dementia. Camptocormia was reported to develop after the clinical onset of PD. No correlation was found between the degree of trunk flexion and age, duration of PD, UPDRS motor score, HY staging, and l-dopa treatment duration and dose. As a risk factor, the study identified previous vertebral surgery. Camptocormia, a relatively common sign in PD seems to be related to the clinical severity of PD.