This case report describes a 44-year-old woman with primary spinal cord malignant melanoma localized in the lumbar region. This is a very rare lesion. The patient presented with back pain and slight weakness in her lower extremities. Magnetic resonance imaging showed hyperintense signals on T1-weighted images and hypointense signals on T2-weighted images. The entire tumor was removed surgically. The patient's postoperative clinical examination revealed mild neurological improvements. Histopathological investigations confirmed the tumor was a malignant melanoma. When treating common lesions of the lumbar spinal cord with a benign appearance, surgeons should be aware of the potential for malignant tumors.