Background: Patients with chronic obstructive pulmonary disease (COPD) may display a motor and/or cognitive disadvantage during dual tasking. However, studies investigating dual task are quite limited in patients with COPD. Aims: To compare cognitive and motor performances (i.e., muscle force production and functional balance/mobility together with a cognitive task) in dual task between patients with COPD and healthy controls. Methods: Thirty-five clinically stable patients with COPD and 27 age- and sex-matched healthy controls participated in this cross-sectional controlled study. The muscle force production (knee extension muscle strength assessed with an isokinetic strength dynamometer) and functional balance/mobility (Timed Up and Go (TUG) test) were performed with and without a cognitive task. Dual-task interference (DTI) was assessed. Additionally, the rate of correct responses per second (RCR) was calculated to evaluate cognitive performance. Results: The decrease in RCRmuscle force production values was greater in the COPD group compared with the control group (p = 0.045). Similarly, the cognitive DTI in muscle force production test was higher in the control group than in the COPD group (p < 0.001). There was no significant difference in other outcome measures between the two groups (p > 0.05). Conclusion: The study results indicate that in individuals with COPD, cognitive performance deteriorations are more pronounced than motor performance defects during dual tasking. Further studies are needed to investigate the effects of dual task taking into account this disadvantage in patients with COPD rather than focusing solely on motor performance.