Ovarian metastasis as the first manifestation of a lung adenocarcinoma is an exceptionally rare condition and is often difficult to distinguish from primary ovarian carcinoma. Metastatic cancers of the pituitary gland are also very rarely recognized. This case concerns a 30-year-old woman who exhibited a unilateral ovarian mass that was initially diagnosed as a well- to moderately- differentiated mucinous adenocarcinoma. A month later, she was found to have a lung cancer. A year later, she developed a solitary pituitary mass. After immunohistochemical staining for thyroid transcription factor-1 (TTF-1), she was diagnosed with pulmonary adenocarcinoma with metastases to her right ovary and pituitary gland. This could be the first case of primary lung adenocarcinoma metastasis to two unusual secondary sites, the ovary and pituitary gland, without widespread systemic metastasis. In the differential diagnosis of an ovarian adenocarcinoma, metastatic carcinoma from the lung should be considered. Immunohistochemical staining for TTF-1 would be helpful as well.