Objective To study the protective effect of penehyclidine hydrochloride (PHCD) against acute lung injury induced by lipopolysaccharide (LPS) in rats. Methods 36 Sprague Dawley (SD) rats were randomly divided into control group, LPS-induced shock group (LPS group), and PHCD treated group (PHCD group). Rat shock model was prepared by intraperitoneal injection of LPS (5 mg/kg). The rats of PHCD group were treated with PHCD (1.0 mg/kg) by caudal vein injection. Rat blood gas analysis was performed 6 hours after the injection. Lung wet/dry mass ratio (W/D) was detected after the rats were sacrificed. The levels of tumor necrosis factor α (TNF-α), interleukin 8 (IL-8), and IL-6 in bronchoalveolar lavage fluid (BALF) were tested by ELISA. The lung tissue inflammation was observed by HE staining. The expression of inducible nitric oxide synthase (iNOS) was detected by real-time quantitative PCR and Western blot analysis. Results Compared with the control group, lung W/D and blood lactate acid (LAC) increased significantly in the LPS group, while the blood pH and the arterial oxygen partial pressure (PaO) decreased markedly. The levels of TNF-α, IL-8 and IL-6 significantly increased in lung BALF of the LPS-induced rats, and the expression of iNOS increased significantly. HE staining showed that LPS treatment caused pulmonary edema, congestion and inflammatory cell infiltration. After PHCD treatment, lung W/D and LAC were reduced; the pH and PaO were elevated compared with LPS-induced rats; the levels of TNF-α, IL-8 and IL-6 in BALF were evidently down-regulated; the expression of iNOS decreased obviously. HE staining showed that the lung inflammation was attenuated by PHCD treatment. Conclusion PHCD attenuates lung injury by inhibiting LPS-induced lung inflammation.