Background:Smoking is a well-established risk factor for pulmonary disease, yet the specific differences in pulmonary function and anatomical variations between smokers and non-smokers require further elucidation. Objectives: This study aims to compare pulmonary function and anatomical lung variations in smokers versus non-smokers. Methods: An observational study was conducted with 100 participants, divided equally into smokers (n=50) and non-smokers (n=50). Demographic data were collected, and pulmonary function tests (PFTs) were performed, including Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV1), FEV1/FVC ratio, and Peak Expiratory Flow (PEF). Chest CT scans assessed anatomical variations, such as emphysema, bronchial wall thickening, and pulmonary nodules. Results: Smokers had a mean age of 45.3 years (±10.2) and a mean pack-year history of 20.4 (±8.7). PFTs showed significantly lower mean FVC (3.4 ± 0.6 L vs. 4.2 ± 0.5 L, p < 0.001), FEV1 (2.7 ± 0.5 L vs. 3.9 ± 0.4 L, p < 0.001), and PEF (380.2 ± 50.1 L/min vs. 460.7 ± 45.3 L/min, p < 0.001) in smokers compared to non-smokers. The FEV1/FVC ratio was also lower in smokers (79.4%± 5.3 vs. 92.8% ± 4.7, p < 0.001). Anatomical differences revealed that smokers had higher incidences of emphysema (70% vs. 10%, p < 0.001), bronchial wall thickening (56% vs. 14%, p < 0.001), and pulmonary nodules (30% vs. 6%, p < 0.001). Conclusion: The study demonstrates significant adverse effects of smoking on pulmonary function and lung anatomy. These findings underscore the critical need for smoking cessation programs to reduce smoking-related morbidity.