Abstract: Malignant melanoma is a potentially aggressive and lethal malignancy deriving from melanocytic cells. Although it comprises only 3% of all cutaneous malignancies diagnosed each year, malignant melanoma contributes to 75% of all skin cancer deaths. In the last decades, there have been advances in immune checkpoint inhibitor (ICPI) development in treating melanoma metastases. ICPI such as programmed cell death ligand-1 (PD-L1) is primary membrane-bound protein expressed in dendritic cells and monocytes. Programmed cell death protein- 1 (PD-1) inhibitors or PD-L1 inhibitors will clinically improve treatment response and overall survival rates in many types of tumors. Nowadays, PD-L1 is being intensively used in cancer patient management revolution, especially in melanoma and non small cell lung cancer. Therefore, the researchers were interested in assessing the relationship between PD-L1 immunohistochemical expression and clinicopathology of malignant melanoma patients in General Hospital Haji Adam Malik Medan. Objective: To analyse the relationship between PD-L1 immunohistochemical expression and clinicopathology characteristics of malignant melanoma in General Hospital Haji Adam Malik Medan.