Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor. Although IMT generally exhibits benign biological behavior, some IMT patients may develop local recurrence or even distant metastasis. Surgery is the most common therapeutic approach. However, additional treatment options are necessary for those who are unable to undergo surgical treatments. Microwave ablation (MWA) is a developing treatment option for unresectable lung cancer. Compared with radiofrequency ablation (RFA), MWA possesses many advantages including larger ablation zones, shorter heating times, and less susceptibility to heat sink. Herein, we reported the case of an 80-year-old male patient who presented with a mass in the right lower pulmonary lobe and right pleural effusion. The maximum diameter of the mass was 53.76 mm, and the patient's main complaint was fatigue for 2 months. Blood test showed severe anemia (hemoglobin: 79 g/L) and hypoproteinemia (albumin: 27.7 g/L). After undergoing blood transfusion, supplementation of albumin, thoracical puncturing and piping, the patient's nutritional condition was improved (hemoglobin, 95 g/L; serum albumin, 29.9 g/L). The pathological diagnosis was pulmonary IMT by percutaneous lung biopsy. The patient was successfully treated with three rounds of percutaneous MWA and has no evidence of recurrence nearly 3 years later. This case has expanded the therapeutic options for elderly patients with pulmonary IMT. Percutaneous MWA monotherapy might serve as an emerging treatment strategy for medically inoperable patients.