Background and Purpose: To decrease intraoperative and perioperative morbidity that is associated with laparoscopic partial nephrectomy (LPN), clamping of the renal hilum has been advocated. It has been suggested, however, that renal hilar control is not necessary in all patients. We compared the perioperative and pathologic results of 21 consecutive patients who underwent LPN with or without renal hilar clamping at our institution. Patients and Methods: Twenty-one patients underwent LPN over a 24-month period. Of these, 11 LPNs were completed without hilar control while 10 needed hilar clamping. Renal hilar control was deemed necessary if the depth of tumor invasion was greater than 50% of the renal parenchyma on CT or MRI. Only the artery was clamped. We retrospectively analyzed the intraoperative, perioperative, and the pathologic results. Results: The mean tumor size was 2.6cm (range 0.8-4.2cm) in the nonclamped group and 2.3cm (range 1.5-3cm) in the clamped group. The mean operative time was 174 minutes (range 95-270min) in the nonclamped group and 232 minutes (range 180-270min) in the clamped group. The mean ischemia time was 29 minutes (range 21-45min) in the clamped group. The mean postoperative serum creatinine level was 1.1mg/dL (range 0.7-2.0mg/dL) in the nonclamped and 1.1mg/dL (range 0.7-1.8mg/dL) in the clamped group. Postoperative transfusion was not needed. In one patient in the nonclamped group and in three patients in the clamped group, urine leak occurred. In the nonclamped group, 7 of the 11 procedures were for benign tumors while only 2 of the 10 lesions in the clamped group were benign. Conclusions: LPN can be performed safely in selected patients without clamping the hilum. Tumors that need cross-clamping of the renal hilum were more likely to be malignant. We suggest that the decision to clamp the hilar vessels should be made based on each patient's characteristics and radiologic findings.