Despite extensive studies, there is no effective treatment currently available other than pirfenidone for idiopathic pulmonary fibrosis. A protective effect of pantothenic acid and its derivatives on cell damage produced by oxygen radicals has been reported, but it has not been tested in bleomycin (BLM)--induced pulmonary fibrosis in rats. Therefore, we aimed to investigate the preventive effect of dexpanthenol (Dxp) on pulmonary fibrosis. Thirty-two rats were assigned to four groups as follows: (1) control group, (2) dexpanthenol (Dxp) group; 500 mg/kg Dxp continued intraperitoneally for 14 days, (3) bleomycin (BLM) group; a single intratracheal injection of BLM (2.5 mg/kg body weight in 0.25-ml phosphate buffered saline), and (4) BLM + Dxp-treated group; 500 mg/kg Dxp was administered 1 h before the intratracheal BLM injection and continued for 14 days i.p. The histopathological grades of lung inflammation and collagen deposition, tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and myeloperoxidase (MPO) were measured. BLM provoked inflammation and collagen deposition (p < 0.0001), with a marked increase in myeloperoxidase (MPO) activity resembling increased inflammatory activity (p < 0.0001), which was prevented by Dxp (p < 0.0001, p = 0.02). BLM reduced tissue activities of SOD, GPx, and CAT compared to controls (p = 0.01, 0.03, 0.009). MDA was increased with BLM (p = 0.003). SOD (p = 0.001) and MDA (p = 0.016) levels were improved in group 4. The CAT levels in the BLM + Dxp group were close to those in the control group (p > 0.05). We showed that Dxp significantly prevents BLM-induced lung fibrosis in rats. Further studies are required to evaluate the role of Dxp in the treatment of lung fibrosis.