A series of cases is presented which illustrates unusual aspects in the presentation, diagnosis, and management of renal cell carcinoma. The entire "classic triad" of flank pain, gross hematuria, and palpable mass was not present at the time of diagnosis in any of the patients. Moreover, in only three patients did the initial clinical findings raise the suspicion of renal cell carcinoma. A diagnosis of polycystic kidney disease, cardiac failure, glomerulonephritis, analgesic abuse, and perirenal hemorrhage obscured the primary diagnosis in the other five patients. In four patients the tumor was probably present from 3 to 12 years before detection. These findings emphasize that knowledge of the hematologic, humoral, immunologic and vascular abnormalities induced by this tumor may provide a clue to early diagnosis. The systematic use of excretion urography, nephrotomography, ultrasonography, renal scanning, renal arteriography and cyst puncture then may allow the accuracy of radiologic diagnosis of this tumor to approach 100%. Lastly, the therapy of choice for this tumor is radical nephrectomy. Excision of apparently solitary metastases also may sometimes be feasible. However, partial nephrectomy to remove tumor in a solitary kidney was performed in one patient to avoid the need for end-stage kidney treatment. Where nephrectomy renders the patient anephric, chronic hemodialysis and renal transplantation should be considered as potential measures to sustain life. While hormonal agents, chemotherapy, and radiation therapy sometimes provide palliation, their use generally has been disappointing.