Objective To evaluate the feasibility and efficacy of intraoperative ultrasonography in laparoscopic partial nephrectomy (LPN) for intrarenal tumors. Patients and methods All patients who underwent LPN for renal tumors in our institution from January 2010 to October 2016 were assessed retrospectively. Patients were divided into two groups, the first with totally intrarenal tumors (TIT group), defined as a solid renal mass with no exophytic element on both preoperative and intraoperative evaluations, and the second with exophytic tumors (control group). General information and perioperative data of the two groups were compared, including tumor characteristics, operative time, estimated blood loss, warm ischemia time and pathological findings. Intraoperative laparoscopic ultrasonography (ILUS) was used to precisely locate and delineate the TIT border, as well as seeking for other suspected lesions. Results We identified 583 patients who underwent LPN in our center, including 46 in the TIT and 537 in the control group. All patients in the TIT group were evaluated by ILUS, and all TIT procedures were successfully performed with only one conversion to open surgery. The mean tumor sizes in the TIT and control groups were 2.42 +/- 0.46 cm and 3.29 +/- 1.43 cm (p < 0.001), respectively. The TIT group's R.E.N.A.L. nephrometry score was higher than that of the control group (median 8.5 vs 6.0, p < 0.001), and their mean operation times were 127.2 +/- 16.0 min and 120.1 +/- 19.2 min, respectively. Mean estimated blood loss was higher in the TIT than in the control group (161.3 ml vs 136.6 ml, p = 0.003). Mean warm ischemia time differed in the TIT and control groups (22.2 +/- 6.4 vs 20.6 +/- 4.7 min, p = 0.105), but not significantly. Rates of open conversion and positive margins, as well as rates of major postoperative complications, pathological findings, and 1-month changes in renal function, were similar in the two groups. Conclusion Intraoperative ultrasonography is technically feasible in patients undergoing LPN for TITs. This method may reduce the need for radical nephrectomy in patients with endogenic renal masses.