Background: Unilateral renal tumor cryoablation and contralateral radical nephrectomy of bilateral renal tumors were performed by transumbilical three-dimensional (3D) multichannel laparoendoscopic single-site (LESS) surgery, in an attempt to verify the feasibility and safety of the procedure, sum up the operational experience, and evaluate the surgical outcome. Case Presentation: This was a 47-year-old female patient with a body mass index of 27.34 kg/m2 without backache, low back pain, hematuria, urinary urgency, frequent urination, dysuria, and other symptoms. Contrast-enhanced CT scan of the kidney on admission showed four masses in the left kidney and two masses in the right kidney. Preoperative serum creatinine (SCr) was 87 μmol/L. Operation was performed under general anesthesia by first laying the patient in a left lateral position. A 2-cm longitudinal transumbilical skin incision was made to expose the right kidney for complete dissection of the two tumors. First, puncture biopsy was performed, and then two freeze-thaw cryoablation cycles for the two tumors were performed. At last, the patient was laid in a right lateral position for radical nephrectomy of the left kidney. The operative duration, cryoablation time, and estimated blood loss were 200 minutes, 40 minutes, and 100 mL, respectively. Postoperative pathological examination revealed clear-cell renal cell carcinoma. The right glomerular filtration rate tested was 42.36 mL/minute and SCr was 131 μmol/L at day 5 after surgery. There was no evidence of contrast enhancement at the cryoablative region as shown by renal contrasted CT scan performed 4 days after surgery and renal contrasted MRI scan performed 6 weeks after surgery, indicating that there was no tumor remnant or recurrence. Conclusion: Our preliminary experience shows that the treatment of bilateral renal tumors with unilateral renal tumor cryoablation and contralateral radical nephrectomy by transumbilical 3D LESS is safe, feasible, and effective. It may prove to be a viable option for patients with significant comorbidities and an insensitive treatment intention.