We report a case of transitional papillary carcinoma of the distal left ureter. The histological and ultrastructural features were seen and compared by SEM and TEM. Observations confirm the data of literature that the deep cells of neoplasm are a normal morphological finding while the superficial cells do not have the characteristics present in normal transitional cells. In addition, SEM shows small groups or single cells with "pleomorphic microvilli" on the cell surface. These, in ureter, confirm the studies of many authors who have observed these abnormalities in carcinomas of several organs like breast, colon, liver and mesothelium.