Objectives To evaluate the utility of routine intraoperative frozen-section histologic analysis during partial nephrectomy to ensure negative surgical margins. Partial nephrectomy has gained acceptance for surgical treatment of small renal cancers. Many surgeons send specimens for intraoperative frozen section histologic analysis to ensure negative margins. Methods We reviewed the records of 78 patients who underwent partial nephrectomy for presumed malignancy. Patient demographics, intraoperative findings, and pathologic and clinical outcomes were analyzed. Results Seventy-nine partial nephrectomies were performed in 78 patients. Frozen sections were obtained intraoperatively in 76 cases. In 1 case (1.3%), a single margin was interpreted as positive for carcinoma, prompting deeper resection. The final histopathologic finding was interpreted as angiomyolipoma rather than carcinoma. The final pathologic examination revealed renal cell carcinoma in 52 (66%) of 79 cases. The mean oncologic follow-up was 16.2 months. One local recurrence was noted (1.9%). It arose in the resection bed 19 months after removal of a 4.5-cm tumor (pathologic Stage T3a). Both intraoperative frozen section margins and final pathologic margins were negative in this case. One patient developed pulmonary metastases and represented the only metastatic recurrence, as well as the only cancer-related death in our cohort (1.9%). Conclusions Our data suggest that when partial nephrectomy is performed with attention to excising a perimeter of grossly normal-appearing parenchyma, sending specimens for intraoperative frozen section analyses may provide an unnecessary expense without providing meaningful, reliable information. Additional studies, including larger cohorts and extended follow-up, are needed to support these results. © 2004 Elsevier Inc.