The purpose of this study was to develop a short questionnaire for psychosocial functioning in patients with Parkinson's Disease (PD). The SCales for Outcomes in Parkinson's disease-PsychoSocial questionnaire (SCOPA-PS) was tested in a survey and compared with other instruments and with medical information. This survey was sent to 205 patents with idiopathic PD. Eighty-six percent of the questionnaires were returned. Cronbach's alpha was 0.83. Two-week test-retest reliability was 0.85 (intraclass correlation coefficient). Construct validity with other scales (Spearman's rho) was 0.82 for the Parkinson's Disease Questionnaire-39-item version (PDQ-39), 0.76 for the PDQ-8, 0.69 for the Hospital Anxiety and Depression Scale, -0.61 for the Euroqol, and -0.60 for a visual analogue scale evaluating Quality-of-Life. The summary index revealed a significant increase with increasing disease severity. The SCOPA-PS is a new, short psychosocial questionnaire for patients with PD with good clinimetric properties.