OBJECTIVE Chlamydia psittaci (Cps) feeds on gram-negative aerobic cells. Respiratory inhalation of Cps or close contact with infected animals can cause psittacosis in humans. Given its challengeable early diagnosis and rapid progression, misdiagnosis or improper antibacterial drugs may lead to multi-organ dysfunction with a high mortality. METHODS A pregnant woman at 29+1 weeks of gestational age had a fever. CT images of the chest showed lamellar consolidations in the inferior lobe of the right lung, light inflammation in the middle lobe of the right lung. Negative results were obtained from multiple times of blood and sputum culture. Next generation sequencing (NGS) results identified that Cps caused severe pneumonia, which was alleviated by specific antibiotic treatment. CONCLUSIONS Cps can cause severe pneumonia in the pregnant woman and be cured through precise antibiotic treatment. NGS is efficient in the rapid identification of pathogens and accurate diagnosis when bacteriological culture fails.