Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality among chronic diseases. Cognitive dysfunction worsens its prognosis by affecting medication compliance and quality of life. The aim of our work was to assess cognitive function in patients followed for COPD and to determine the areas most affected. We conducted a cross-sectional study in the outpatient department of pulmonology at the CHU Mongi Slim La Marsa in Tunisia. Cognitive function was assessed using the Mini Mental State Examination (MMSE) questionnaire translated into Tunisian dialect. 150 patients were collected (37% illiterate), with an average age of 66 years. The average smoking rate was 60 ± 33.9 BP and 33.3% of patients had cardiovascular comorbidities. Fifty-four percent of the patients were classified as GOLD D. Cognitive dysfunction was detected in 10.7% of the cases (13.3% in the educated and 5.8% in the illiterate). We were able to conclude that cognitive disorders were frequent in patients followed up for COPD in Tunisia and that their screening should be systematic in consultation.