Objective To observe the CT features of mycoplasma pneumoniae pneumonia. Methods CT features of 40 adult patients with serologically proven mycoplasma pneumoniae pneumonia were retrospectively reviewed. Results The most common CT findings of mycoplasma pneumoniae pneumonia were ground-glass opacity (34/40, 85.00%) and consolidation (28/40, 70.00%). The other findings included nodules (18/40, 45.00%), thickening of the bronchovascular bundles (6/40, 15.00%), interlobular septal thickening (6/40, 15.00%), mediastinal lymphadenopathy (6/40, 15.00%) and pleural effusion (4/40, 10.00%). Most of the ground-glass opacity and consolidation showed tendency of lobular distribution and involving the lower lobes. In some patients, the absorption of the lesions was slower than the relief of symptoms. Conclusion CT findings of mycoplasma pneumoniae pneumonia have some features, and can provide help for the diagnosis of mycoplasma pneumoniae pneumonia.