Background: The events in pregnancy provoke one of the best instances of selective anatomical, physiological and biochemical adaptations that occur throughout pregnancy and substantial changes in respiratory physiology are a part of the same processThe present study was conducted to assess the pulmonary functions of women in the third trimester of uncomplicated pregnancy. Materials & Methods: 65 pregnant women in their third trimester of uncomplicated pregnancywere kept in group I and non-pregnant women (control) in group II. A detailed history was recorded and complete clinical examination was done. The height as well as weight of the subject were noted. The assessment of PFT was carried out by Medspiror. Parameters such as FVC, FEV1, FEF25%-75%, PEFR and FEV1/FVC ratio was recorded. Results: The mean height was 164.3 cms in group I and 159.5 cms in group II, weight was 67.5 kgs in group I and 58.4 kgs in group II, hemoglobin was 11.3 g/dl in group I and 11.8 g/dl in group II, BMI was 27.4 kg/m2 in group I and 22.3 kg/m2 in group II. The mean heart rate was 81.3 beats/min in group I and 81.5 beats/min in group II. SBP was 120.4 mm Hg in group I and 118.2 mm Hg in group II and DBP was 78.6 mm Hg in group I and 72.6 mm Hg in group II. The difference was significant (P< 0.05).FVC (% predicted) was 90.4 and 95.2, FEV1 (% predicted) was 91.3 and 93.5, FEV1 / FVC ratio (actual) was 82.6 and 87.3, PEFR (% predicted) was 90.4 and 96.2, FEF25-75% (% predicted) was 87.3 and 93.4 in group I and group II respectively. The difference was significant (P< 0.05). Conclusion: Respiratory parameters are significantly compromised due to gravid state in the last trimester of pregnancy.