Aim: Nowadays, there are still some difficulty to distinguish smoker asthmatic patients and COPD. Differentiation of these disorders is very important as their treatment choices are different. The aim of this study is to investigate the presence of auscultation together with pulmonary function test (PFT) findings and the power of these findings in distinguishing asthma and COPD patients. Methods: 585 patients diagnosed of asthma and COPD according to international guidelines in our out-patient clinic were reviewed and their semptoms, risk factors, physical exam findings and PFTs were evaluated. Results: The study consisted of 294 women and 291 men. The mean age of patients was 41.2±14.5 years. 433 patients were asthmatic and 152 had COPD. While there was a significantly concordance between auscultation and PFTs in non-smoker patients with asthma (p=0.00), we didn’t find any accordance in smoker patients with asthma and COPD (p>0.05), If auscultation was normal and only FEF25-75 parameter showing obstruction in PFT was lower this condition was found more specific for asthma (without cigarette influence) than COPD (p=0.000). Conclusion: Our data shows that abnormal findings of auscultation and PFTs were more concordance in non-smoker patients with asthma. This indicates that PFTs (decrease in FEF25-75) may be utilized noninvasively to distinguish asthma and COPD cases in outpatient clinics.