Background Pneumonia caused by the 2019 novel Coronavirus (COVID‐2019) shares overlapping signs and symptoms, laboratory findings, imaging features with influenza A pneumonia. We aimed to identify their clinical characteristics to help early diagnosis. Methods We retrospectively retrieved data for laboratory‐confirmed patients admitted with COVID‐19–induced or influenza A–induced pneumonia from electronic medical records in Ningbo First Hospital, China. We recorded patients' epidemiological and clinical features, as well as radiologic and laboratory findings. Results The median age of influenza A cohort was higher and it exhibited higher temperature and higher proportion of pleural effusion. COVID‐19 cohort exhibited higher proportions of fatigue, diarrhea and ground‐glass opacity and higher levels of lymphocyte percentage, absolute lymphocyte count, red‐cell count, hemoglobin and albumin and presented lower levels of monocytes, c‐reactive protein, aspartate aminotransferase, alkaline phosphatase, serum creatinine. Multivariate logistic regression analyses showed that fatigue, ground‐glass opacity, and higher level of albumin were independent risk factors for COVID‐19 pneumonia, while older age, higher temperature, and higher level of monocyte count were independent risk factors for influenza A pneumonia. Conclusions In terms of COVID‐19 pneumonia and influenza A pneumonia, fatigue, ground‐glass opacity, and higher level of albumin tend to be helpful for diagnosis of COVID‐19 pneumonia, while older age, higher temperature, and higher level of monocyte count tend to be helpful for the diagnosis of influenza A pneumonia. Fatigue, ground‐glass opacity and higher level of albumin tend to be helpful for diagnosis of COVID‐19 pneumonia, while older age, higher temperature, and higher level of monocytes count tend to be helpful for the diagnosis of influenza A pneumonia.