Aim: Chronic obstructive pulmonary disease (COPD) is a progressive disease characterized by restriction of functional capacity and exercise intolerance. 6-minute walk distance (6MWD) is a quick and safe method used to evaluate the functional capacity in COPD. The aim of this study was to reveal the factors affecting 6MWD in stable COPD. Material and Method: Patients with COPD applied to chest diseases outpatient clinic between September 2012 March 2013 who were in stable stage were included in the study. They were staged according to Global Initiative for Obstructive Lung Disease (GOLD). 6MWD test, arterial blood gas measurements and pulmonary function tests were performed for all subjects. Results: A total of 154 patients were enrolled in the study 150 of them were males and 4 were females. The mean age was 61.6 (35-85) years. Patients were divided into two subgroups mild-moderate group and severe-very severe group. 6MWD test of mild-moderate group was 41 meters more than severe-very severe group. The difference was statistically significant (p= 0.001). Correlation analysis was performed to reveal the factors affecting 6MWD test. It was negatively correlated with age and arterial partial pressure of carbon dioxide (PaCO2) (respectively p< 0.001, p= 0.001) and was significantly positive correlated with pulmonary function parameters, arterial partial pressure of oxygen (PaO2) (p< 0.001) and oxygen saturation (p < 0.001). Discussion: Age, pulmonary function test and arterial blood gas parameters affect 6MWD.