Background & Aim: Idiopathic pulmonary fibrosis (IPF) leads to the misplaced deposition of the extracellular matrix and the stiffness parenchyma and the creation of scarring (fibrosis) in the lung. This study was conducted with the aim of investigating the effectiveness of different doses of H.atra body wall extract on bleomycin-induced pulmonary fibrosis. Experimental: The animals were randomly divided into six groups (n = 6). Group 1 (Control) was administered normal saline intratracheally (single dose) on day 1, Group 2 (bleomycin) received single dose of bleomycin (BLM, 7.5 IU/kg) intratracheally and daily doses of normal saline by gavage, Group 3 (pirfenidone) received single dose of BLM (7.5 IU/kg) intratracheally and daily doses of pirfenidone by gavage, Groups (4, 5 and 6) received single dose of BLM (7.5 IU/kg) intratracheally and received daily doses of H. atra extract (50, 100 and 200 mg/kg, respectively). Finally, the rats were euthanized, and the lung tissues were taken out for histological and biochemical assessments. Results: Histological tests showed that bleomycin could induce marked pulmonary fibrosis within two weeks. Administration of hydroalcoholic extract of H. atra body wall reduced these damages in lung tissue in a dose-dependent manner. The best results were obtained for 200 mg/kg per day of H. atra body wall extract. Recommended applications/industries: Based on the present findings, H. atra body wall extract can reduce the toxic effects of bleomycin on lung tissues. Such effects can be attributed to the compounds with anti-inflammatory and antioxidant properties in this plant. Manuscript profile