Nowadays lung cancer is regarded as the leading cause of cancer-related death, leading to a mortality number of nearly 1.8 million annually [1]. Lung adenocarcinoma, as a relatively common pathological type of lung cancer in clinical practice, shows a gradually increasing tendency and ranks top in both morbidity and mortality rate among all malignant tumors[2]. In recent years, rapid progress in tumor immunotherapy and tracheoscopy intervention technology provide more possibilities for the treatment of lung adenocarcinoma. Here we report an 83-year-old patient diagnosed with lung adenocarcinoma stage IV who achieved partial clinical remission after receiving 4 periods of systemic intravenous administration and 2 periods of intratumoral administration of tirellizumab under tracheoscopy. By follow-up on August 24, 2024, the patient’s tumor was still shrinking without any treatment-related adverse reactions. Based on this case, it is suggested that systemic intravenous tirelizumab combined with tracheoscopic intratumoral injection may provide a safe and effective strategy for patients with lung adenocarcinoma, especially for those who cannot tolerate chemotherapy or surgery. However, further prospective studies and more clinical experiments are still needed to confirm our hypothesis.