Most of the mixed ground-glass nodules are malignant, while most of the pure ground-glass nodules are caused by benign diseases. Lung nodules are lung masses less than or equal to 3 cm in size detected by chest CT or other imaging studies, and can be categorized into solid nodules, pure ground-glass nodules, and mixed ground-glass nodules with both solid and ground-glass components according to their density. Ground-glass nodules may be caused by benign diseases such as inflammatory exudation, tuberculosis, and sarcoidosis in the lungs, or malignant tumors such as bronchopulmonary carcinoma and metastatic carcinoma in the lungs. The risk of malignancy differs between pure and mixed ground glass nodules, with a malignancy rate of about 18% for pure ground glass nodules and a higher malignancy rate of about 64% for mixed ground glass nodules. The risk of malignancy of ground glass nodules is also related to the size and shape of the nodule, the patient’s age, gender, and family history. Patients are advised to consult their specialists in a timely manner for individual and lesion-specific evaluation and aggressive treatment.