The patient, a 54-year old woman died after open heart surgery. A minimal thyroid carcinoma with lymph node metastasis was incidentally found at autopsy. The tumor was in the left lower pole, it was 0.9 mm in diameter. Histologically, it was follicular carcinoma. Metastasis was found in three lymph nodes around the tumor. A review of the literature suggests this to be the smallest follicular carcinoma reported to data.