Primary malignant melanoma of the parotid gland (PGMM) is extremely rare, with a poor prognosis. Surgery is the main treatment option followed by adjuvant treatments such as radiotherapy, but which adjuvant treatment to be optimal is still controversial. In this case, a 63-year-old male PGMM patient was first misdiagnosed as a "myoepithelial tumor" and then treated with surgery, postoperative immunotherapy (sintilimab), chemotherapy, and radiotherapy successfully. The progression free survival was more than 19 months without signs of metastasis or recurrence to date. To our best knowledge, this is the first report of postoperative immunotherapy combined with chemotherapy and radiotherapy for PGMM. Our case indicated that combination therapy including surgery, adjuvant immunotherapy (sintilimab) combined with chemotherapy and radiotherapy may be a potential treatment option for PGMM, which needs further research.