A very common questionnaire, used to evaluate the health status of Chronic Obstructive Pulmonary Disease (COPD) patients, COPD assessment test (CAT), was applied to finding correlations between the items of CAT and other tests used in the same category of COPD patients. A sample of 56 male COPD patients, aged between 51 and 74 years, mean 63.86 (�5.55), half of them receiving long-term oxygen therapy, using transparent, hypoallergenic plastic masks or nasal cannulas, answered to CAT mostly choosing single items, statistically significant correlated with the Hospital Anxiety and Depression Scale scores (HADs), like walking up hills and stairs (r = 0.412, p[ 0.01), doing activities at home (r = 0.329, p[ 0.01), confidence leaving my home (r = 0.409, p[ 0.001), sleep (r = 0.277, p[ 0.01), and energy (r = 0.387, p[ 0.01), but CAT item walking up hills and stairs correlated better to 6 min walking distance (6MWD) (r = -0.581, p[ 0.01). The most significant correlations were found between 3 items of CAT as walking up hills and stairs, limitations doing activities at home and confidence leaving home in a most powerful and depression scores and 6MWD.