Abstract: Objective To report the recombinant human tumor necrosis factor-alpha (rmhTNF-α) in treatment of malignant pleuroperitoneal cavity effusion in an elderly patient with non-small cell lung cancer (NSCLC). Methods A drainage tube was placed in a lung cancer patient with pleuroperitoneal cavity effusion admitted to our department in 2010 to drain the pleuroperitoneal cavity effusion every day with its volume recorded, followed by injection of 2 mg and 5 mg dexamethasone and 20 ml normal saline containing 2×10⁶ U/5×10⁶ U rmhTNF-α into the pleuroperitoneal cavity. The therapeutic effect was assessed by measuring the volume of drained pleuroperitoneal effusion, imaging, infusion amount of blood products, and blood transfusion interval. Results The rmhTNF-α could effectively control the malignant pleuroperitoneal cavity effusion in patients with progressive lung cancer, with their pleuroperitoneal cavity effusion and infusion amount of blood products reduced, and their blood transfusion interval shortened after treatment as shown in lung CT and abdominal ultrasongraphy(P＜ 0.01). Conclusion The rmhTNF-α is effective for malignant pleuroperitoneal effusion failing to conventional treatment. However, its mechanism is still unclear, thus needing to be further studied.