Methods: This study, which was conducted between July 2008 and July 2013 at Istanbul Haydarpaşa Numune Training and Research Hospital, included 795 patients (454 males, 341 females; mean age 72.2±11.4 years; range 26 to 99 years) who were diagnosed with chronic obstructive pulmonary disease and had acute respiratory failure before and after the smoking ban of 16 July 2009. Patients’ age, gender, socioeconomic status, smoking/cessation status, number of exacerbations, chest X-ray findings, arterial blood gas analyses, duration of hospital stay, and leukocyte count were recorded.

Results: There was a statistically significant difference in smoking status of patients before and after the smoking ban (p=0.002; p<0.01). The rate of smokers declined year by year, while there was an increase in the rate of ex-smokers. The number of exacerbations in one year before the smoking ban was higher compared to the number of exacerbations in one year after the smoking ban, although the difference was close to statistical significance (p=0.061; p>0.05).

Conclusion: Our study demonstrated that smoking ban reduced the number of patients with chronic obstructive pulmonary disease and number of exacerbations. Therefore, we suggest that prohibiting the use of tobacco products is an important part of the strategy toward the prevention of this disease.