Primary malignant melanoma of vagina is a rare tumor which is easily misinterpretated in routine cytologic examination. We lately experienced a case of primary malignant melanoma of the vagina with direct cervical extension diagnosed by Pap smear. The cervicovaginal smear showed variable sized clusters of epithelial cells or singly scattered abnormal epithelial cells. Most of the tumor cells had round hyperchromatic nuclei with prominent nucleoli and brownish pigments in cytoplasm. The cytologic findings are compared with histologic features of resected specimen.