Objective: To evaluate the therapeutic efficacy of injecting recombinant mutant human tumor necrosis factor (rmhTNF) into pericardial cavity of carcinoma patients with malignant pericardial effusion. Methods: In 20 cases of malignant pericardial effusion, the intrapericardial catheter was inserted into pericardial cavity, and then rmhTNF of 1.5 × 107 U was infused. The infusion was repeated every 5-7 days with the total 4-6 times. If the effusion disappeared, rmhTNF was then used 2 more times and then the intrapericardial catheter was pulled out. Results: Of 20 patients, 14 were complete response (CR), 4 were partial response (PR) and 2 no change (NC). The disappearance of effusion in 6 cases lasted for more than 6months. Conclusion: Injecting rmhTNF into pericardial cavity may be a better way to control malignant pericardial effusion and has mild side effects.