A 37-year-old male patient with pulmonary infection was admitted to Lianyungang Municipal First People’s Hospital on May 28, 2024, and he had lightly high-density shadows in the lower lobe of the left lung during physical examinations 16 days ago. The case was given anti-infective therapy with cefazoxime and levofloxacin (unknown dosage) for 9 days, and chest CT scans displayed progression of infections in bilateral lungs. Following admission, the patient underwent tracheoscopy and next-generation sequencing (NGS) of alveolar lavage fluids identified 522 Trichomonas tenax sequences. The patient had a medical history of periodontal disease and had ingested food with chopsticks used for undercooked meat within the past 2 months. The patient was diagnosed with T. tenax infection complicated with asymptomatic pulmonary infection based on his medical history and auxiliary diagnoses, and was treated with biapenem (0.3 g, 3 times per day) and metronidazole (0.5 g, 3 times per day) for 9 days. Chest CT scans displayed improvements in pulmonary infections, and the case was discharged from hospital because of absence of any other special abnormalities. Following discharge, the patient continued to administer moxifloxacin (0.1 g per day) and metronidazole (0.5 g, 3 times per day) orally. Outpatient follow-up visits showed no discomfort two weeks following discharge, and chest CT scans displayed a clear left lung and calcification in the right lung, with no other obvious abnormalities found.