ObjectiveTo investigate the clinical characteristics and prognosis of pneumocystis pneumonia (PCP) in patients with lymphoma. MethodsTwenty inpatients who were diagnosed as lymphoma with PCP in PLA 307 Hospital from March 2012 to December 2014 were retrospectively analyzed. ResultsAll patients got non-Hodgkin's lymphoma. Specific genes for Pneumocystis jirovecii were found in the sputum of 5 patients and the bronchoalveolar lavage fluid of the other 15 patients. The major clinical presentations were fever (18/20) and dyspnea (13/20). Arterial blood gas analysis showed that all patients had hypoxaemia. There were 10 patients with respiratory failure (10/20), in which 7 patients needed mechanical ventilation (7/20). Four patients died (4/20). All patients were treated by multiple chemotherapy. Fifteen patients (75%) had leukocytopenia, with an average white blood cell (WBC) count of (3.2±2.8)×109/L. The mean lactate dehydrogenase (LDH) level was (374.6±197.2) U/L. The mean APACHEⅡ score was 12.6±4.4. PCP had no significant manifestations under the bronchoscope. Imaging manifestations were ground-glass opacities expanding to periphery from the hila, but the pleura was less involved. Univariate analysis revealed that there were no significant differences in chemotherapy cycle, WBC count or G test between the survival group and the death group. However, serum LDH, APACHEⅡ score, delay diagnosis, and co-infection were statistically significant between the two groups. ConclusionsThe main clinical presentations of PCP patients with lymphoma are fever and progressive exertional dyspnea. High LDH, high APACHEⅡ score, diagnosis delay and co-infection indicate poor prognosis.