Cystadenocarcinoma is a rare malignant tumor that accounts for less than 0.2% of all salivary gland tumors. We report a rare case of cystadenocarcinoma arising in the hard palate. A 63-year-old man was referred to our department for a detailed examination of a 2.5mm mass on the right side of the hard palate. A biopsy was performed based on the clinical diagnosis of papilloma, and the results showed cystadenocarcinoma. Imaging studies showed no cervical lymph node metastasis or distant metastasis. Based on the diagnosis of cystadenocarcinoma, the tumor resection was performed under general anesthesia. Nine years have passed since the surgery, and there has been no sign of recurrence or metastasis.