Kidney cancers are relatively rare and account for only 3% of adult malignancies. Although these tumors are more common in men than in women, with a male:female ratio of 1.5:1, the kidney is a significant source of cancer diagnoses and death in women. In the United States in 2002, it is estimated that 12,700 women will be diagnosed with kidney cancer and 4,400 women will die of the disease. Approximately two thirds of renal carcinomas are now discovered incidentally while patients are being scanned for abdominal or pelvic conditions, making knowledge of this disease even more important for the practicing obstetrician-gynecologist.