ETHNOPHARMACOLOGICAL RELEVANCE: Lianhua Qingke (LHQK), a traditional Chinese medicine, has shown efficacy in treating acute and chronic bronchitis and bronchiolitis. However, the specific mechanism underlying the therapeutic effects of LHQK on severe pneumonia is not clear. AIM OF THE STUDY: Severe pneumonia remains a critical health challenge, particularly in cases progressing to sepsis and septic shock, where host immune responses become dysregulated or dysfunctional. This study aims to evaluate the immunomodulatory effects of LHQK in severe pneumonia. MATERIALS AND METHODS: This research examined LHQK's therapeutic and immunomodulatory mechanisms in patients with severe pneumonia and a lipopolysaccharide (LPS)-induced mouse model of severe pneumonia. Patients with severe pneumonia were randomized into three groups: basal treatment, LHQK-Low dose (12 tablets/day), and LHQK-High dose (24 tablets/day). BALB/c mice were categorized into four groups: control, model, LHQK-Low dose (3.7 mg/kg), and LHQK-High dose (7.4 mg/kg). Clinical efficacy was evaluated by assessing parameters including the value and rate of change in APACHE II score, improvement in chest X-ray or CT, partial pressure of oxygen (PO RESULTS: In comparison to the basal treatment group of patients, LHQK treatment exhibited a reduction in the severity of severe pneumonia and inflammatory status, as evidenced by observations on Chest X-ray or CT scans. Additionally, LHQK treatment led to an elevation in OI, PO CONCLUSION: LHQK demonstrates therapeutic efficacy in severe pneumonia by maintaining structural integrity, suppressing cytokine storms, enhancing intrinsic immunity, reversing T cell exhaustion, and correcting lung immune disorders. These findings significantly substantiate LHQK's potential clinical application in severe pneumonia treatment.