OBJECTIVE: In the present study we assessed the impact of former cigarette smoking on asthma control and treatment effectiveness. METHODS: A total of 104 patients with uncontrolled asthma were included in the study. The group of former smokers consisted of 33 subjects, whereas the never smokers group consisted of 71 subjects of similar age and gender. Spirometry, classification of asthma severity, and control were assessed according to Global Initiative for Asthma (GINA) guidelines. Quality of life was measured with the use of the Saint George Hospital Respiratory Questionnaire (SGHRQ). RESULTS: Asthma was more severe in the group of former smokers both before and after treatment; p < 0.001. Severe asthma (OR 7.8 CI 2.8-21.9) and cigarette smoking (OR 3.5 CI 1.3-9.2) were associated with difficulties in asthma control achievement. Total quality of life significantly improved in the group of non-smokers; p = 0.02, whereas in former smokers this effect was not significant; p > 0.05. CONCLUSION: Cigarette smoking has a persistent, dose-dependent, negative impact on the response to treatment in patients with uncontrolled asthma even after smoking cessation. Smoking cessation should remain the ultimate goal in treatment of asthmatic patients. More efforts should be undertaken to decrease smoking initiation, especially in teenagers.