Introduction. In India, obesity is rapidly escalating in all age groups. Obesity has significant effects on respiratory function and reduces lung volume. Peak Expiratory Flow Rate (PEFR) demonstrates the calibre of the airways and is accepted worldwide as the objective indicator of ventilatory capacity, and is useful for the diagnosis and management of respiratory illness. Objective. The aim of this study was to compare the Peak Expiratory Flow Rates between obese and non-obese females aged 35-45. Materials and method. 40 healthy obese females with BMI ≥30Kg/m 2 and 40 healthy non-obese females with BMI (18.5-24.9 Kg/m 2 ) as controls were included in the study. Subjects with H/o cardiopulmonary illness, asthma, diabetes mellitus, hypertension, smokers, on chronic medication, subjects who had noticeable weight gain / loss over the preceding 3 months, were all excluded. PEFR Measurements were performed using a Mini Wright's Peak Flow Meter. Three readings at 2 minutes intervals were recorded. The maximum of the 3 values were taken as the PEFR. The results were statistically analysed using Students Unpaired t-test. Results. PEFR in obese females (320±28.06 L/Min) was significantly lower than the non-obese females (361±29.17L/Min), which was statistically significant (p=0.000; p<0.05). PEFR was negatively correlated with BMI (Pearson's correlation r = -.127) significant at p<0.01 level. Conclusions. There occurs a significant reduction in PEFR in obese females, compared to non-obese females. This study highlights the need for aggressive reduction of weight in obese females in order to increase respiratory efficiency.