Objective To explore and analyze features of clinical manifestations and auxiliary examination results of patients with Chlamydia psittaci (C. psittaci) pneumonia, and improve the understanding of the disease. Methods Clinical data of 9 patients with C. psittaci pneumonia diagnosed by metagenomic next-generation sequencing (mNGS) in a hospital from June 2019 to August 2021 were retrospectively analyzed. Results Among 9 patients, 7 were males and 2 were females, including a pregnant woman who was 36⁺² weeks pregnancy; patients were aged 25-70 years, with a median age of 63 years; the main clinical manifestations were high fever (n=9), cough (n=9) and expectoration (n=7). Eight patients' leukocyte count was normal, 9 patients' lymphocyte count decreased, 9 patients' C-reactive protein (CRP) increased, 9 patients' erythrocyte sedimentation rate (ESR) increased, 4 patients' procalcitonin (PCT) was normal, 6 patients' aspartate aminotransferase (AST) and alanine aminotransferase (ALT) increased. Chest CT of all patients showed patchy or patchy consolidation. After confirmed by mNGS of blood and bronchoalveolar lavage fluid, monotherapy of doxycycline, moxifloxacin, levofloxacin, and azithromycin were administered for 14-21 days, all patients were cured and discharged from hospital. Conclusion C. psittaci pneumonia has a variety of clinical manifestations and is difficult to be diagnosed, mNGS test can quickly identify the etiology, facilitate the timely initiation of specific anti-infective therapy, reduce antimicrobial use, and improve the prognosis.