Objective: We aimed to investigate the association between physical activity and depression in patients with obstructive sleep apnea syndrome (OSAS). Patients and Methods: Ninety consecutive OSAS patients were recruited from the Sleep Laboratory of the Neurology Department, Erciyes University Medical School, between September 2008 and May 2010. The patients were diagnosed based on polysomnography. Physical Activity Assessment Questionnaire and Beck Depression Scale with an additional form for demographic variables were used as questionnaires. Results: Ten (11.1%) patients with OSAS had depression. Depression was significantly more in female OSAS patients (p= 0.00). There were no significant changes in other demographic (p> 0.05), polysomnographic (p> 0.05) and physical activity variables (p> 0.05) between OSAS patients with and without depression (p> 0.05). No significant correlation between depression and physical activity was found (p> 0.05). Conclusion: Depression was more frequent in female OSAS patients, and physical activity was not associated with depression in OSAS patients.