We report the case of a 69-year-old woman with a Merkel cell carcinoma (MCC) in whom subsequent lymph node metastasis was first diagnosed by 68Ga-Dotatate-PET/CT followed by histopathological confirmation. MCC is an extraordinarily rare and aggressive neuroendocrine tumor of dermal origin with a high rate of postoperative recurrence. Owing to its rarity, the diagnosis of MCC remains a significant challenge. In our case, 68Ga-Dotatate-PET/CT proved clinically useful for diagnosing the lymph node metastasis of a MCC.