Acute exacerbations (AE) affect the prognosis of hospitalized patients with chronic obstructive pulmonary disease (COPD). Pneumonia further affects their prognosis and early diagnosis of pneumonia in AECOPD is important to initiate treatments. This study aimed to examine the differences between hospitalized AECOPD patients with and without pneumonia in order to identify risk factors of pneumonia among hospitalized patients with AECOPD.This was a retrospective case-control study of patients with COPD hospitalized at the respiratory ward of Beijing Shijitan Hospital, Capital Medical University, from October 2010 to October 2013. Patients were divided into the pneumonia and nonpneumonia groups based on exudations or opacities on chest computed tomography (CT) at admission. Data were analyzed using the chi-square test and independent 2-sample ANOVA in SPSS 20.0. Logistic regression analysis was used to identify the factors independently associated with pneumonia. P < .05 was considered statistically significant.A total of 164 patients were included. Smoking history (OR = 2.646, 95%CI 1.153-6.074, P = .022), use of drugs during the stable stage (OR = 0.435, 95%CI 0.216-0.877, P = .020), D-dimer levels (OR = 1.001, 95%CI 1.000-1.002, P = .049), percentage of neutrophils (OR = 0.271, 95%CI 0.078-0.940, P = .040), and magnitude of neutrophils increase (OR = 0.946, 95%CI 0.896-0.999, P = .046) were independently associated with pneumonia in patients with AECOPD. For severe and very severe COPD patients, smoking history (OR = 4.426, 95%CI 1.458-13.435, P = .009), use of drugs during the stable stage (OR = 0.384, 95%CI 0.168-0.877, P = .042), and fever (OR = 0.426, 95%CI 0.187-0.969, P = .023) were independently associated with pneumonia.Smoking history, use of drugs during the stable stage, and percentage of neutrophils are independently associated with CT-diagnosed pneumonia among hospitalized AECOPD patients.