Exogenous lipoid pneumonia occurs rarely in healthy people. In most cases, exogenous lipoid pneumonia is usually caused by aspiration of mineral, vegetable, or animal oil. We report the case of 42-year-old woman, who have experienced lipoid pneumonia after silicon injection into her breast for cosmetic purposes. The patient experienced fever, dyspnea, sputum, and hemoptysis after silicon injection into her breast. Chest computed tomography demonstrated non- segmental distribution of bilateral consolidation in both lung fields. A transbronchial lung biopsy specimen shows foamy microphages in alveolar spaces. Papanicolaous staining of bronchoalveolar lavage fluid showed abundant foamy marcrophages and many neutrophils. With these results, we confirmed lipoid pneumonia was associated with silicon oil injection into breast.