Background: Obesity is a public health issue, contributing to cardiovascular diseases and increased healthcare costs. It can cause systemic complications and adversely affect respiratory function, leading to decreased pulmonary function. This study aims to explore the relationship between obesity and lung function parameters. Methods: This analytical observational study with a cross-sectional approach was conducted at Wahidin Sudirohusodo General Hospital in 2024, involving 47 obese and 40 non-obese patients. Spirometry assessed pulmonary function, excluding those with asthma or COPD. Data were analyzed using descriptive statistics and Chi-Square tests, with significance set at p < 0.05. Results: The study population was predominantly female (51.7%) and aged 30-39 years (50.8%). Among respondents, 16.1% were smokers and 54.0% were obese. A total of 70.1% had normal pulmonary function, and the remaining had mild obstruction, mild to moderate restrictions, or mixed disorders. No significant relationship was found between obesity and pulmonary function parameters, namely VC, FEV1, FVC, and FEV1/FVC with p value ratio exceeding 0.05 between obese and non obese groups. Conclusion: This study found no significant association between obesity and decreased lung function parameters.