Objective To evaluate the clinical characteristics and treatment of Chlamydia psittaci (C. psittaci) pneumonia. Methods Clinical data of 43 patients with C. psittaci pneumonia confirmed by metagenomic next-genera- tion sequencing (mNGS) in a hospital from March 2018 to March 2022 were retrospectively analyzed. Results The mean age of the 43 patients was 55.80 years, with 23 males and 20 females. 18 patients had a clear history of contacting with birds or poultry. The onset months were mostly winter and spring. The most common clinical manifesta- tion was fever, which can be accompanied by symptoms such as cough, muscle soreness, and chills. Blood routine test showed that 28 (65.12%) patients had normal white blood cell count, 21 had an increase in neutrophil count, and 32 had a decrease in lymphocyte count. 43 patients had elevated C-reactive protein level, 26 had elevated alanine transaminase, 32 had elevated aspartate aminotransferase, and 33 had elevated lactate dehydrogenase. 15 patients had respiratory failure, 9 patients progressed to severe pneumonia. Chest high-resolution computed tomography (HRCT) showed consolidation in the unilateral lower lobe of the lung, more in the right lung, and 13 patients complicated with pleural effusion. The main manifestation under bronchoscope was alveolitis with little secretion. In 43 patients, mNGS detected C. psittaci sequence numbers ranging from 1 to 21 269. Quinolone treatment was applied to 40 patients, which was adjusted to doxycycline, minocycline and tigecycline after the pathogen was identified. The median hospitalization time of 43 patients was 13.00 days. All patients showed improvement and were discharged, without reported cases of mortality. Conclusion Most patients with C. psittaci pneumonia are characte-rized by an onset with high fever, lung involvement, and a history of poultry exposure. mNGS enables rapid and accurate pathogen detection. Doxycycline is the preferred choice for treatment, and quinolones are also effective. Some patients can progress to severe cases, but the overall prognosis is good.