INTRODUCTION: Determination of exercise capacity is crucial for chronic obstructive pulmonary disease (COPD) management since it is an indicator of life quality and mortality. Various previously defined tests, including the cardiopulmonary exercise test (CPET), the 6-minute walking test (6MWT), and the incremental shuttle walk test, are used to determine COPD patients' exercise capacity. However, they all have some disadvantages, such as time, personnel, and equipment requirements, limiting their daily practice use. Here, it was aimed to investigate the role of 4-meter gait speed (4mGS) in evaluating exercise capacity in COPD. MATERIALS AND METHODS: We included 40-to-70-year-old COPD patients with no contraindications for exercise testing. We performed the tests at standard intervals without affecting each other's results. We also performed spirometry. We used the modified Medical Research Council Scale, COPD Assessment Test, and BODE index to determine the current status of individuals. RESULT: Twenty-three (female/male= 2/21) subjects aged 58.1 ± 7.3 were included in the study. A statistically significant correlation was observed between 4mGS and peak VO2 values. There was also a statistically significant relationship between 4mGS and 6MWT distance. 4mGS correlated with CAT and BODE scores to represent the general medical status of patients. CONCLUSIONS: Considering its easy applicability and reproducibility, 4mGS seems to be a strong candidate for daily clinical use in monitoring the exercise capacity of COPD patients. Further studies in larger patient groups are needed to support these results.