Objective To assess the safety, feasibility and efficacy of retroperitoneal laparoscopic-assisted mini-incision partial nephrectomy in treatment of R.E.N.A.L. tumors with R.E.N.A.L. score ≥7, and to evaluate its clinical significance. Methods Between January 2011 and November 2012, retroperitoneal laparoscopic-assisted mini-incision partial nephrectomy was performed in 19 R.E.N.A.L. tumor patients with R.E.N.A.L. score ≥7 at our institution. The information of patients was: male/female, 10/9; age (48.5±14.0) years old; body mass index (24.0±2.6) kg/m²; ASA score (1.9±0.4); Charlson co-morbidity index (age-weighted) 0.6±0.2; tumor laterality (L/R) 11/8; maximal diameter (3.3±1.2) cm; R.E.N.A.L. nephrometry score 8.6±0.9; and preoperative estimated glomerular filtration rate (eGFR) (\[104.8±24.0\] mL/\[min·1.73 m²\]). The R.E.N.A.L. pedicle, involved kidney and tumors were exposed by retroperitoneal laparoscopic techniques. A mini-incision was made along the line between the two original subcostal trocar sites. The R.E.N.A.L. pedicle was clamped and ice-slush surface cooling of the kidney was given, by then the tumor resection and R.E.N.A.L. defect reconstruction was finished. Results All the 19 cases were smoothly finished without any intraoperative complications or blood transfusion. The operative time was (220.2±57.5) min, estimated blood loss was (252.6±182.9) mL, R.E.N.A.L. ischemia time was (25.2±6.6) min, and all surgical margin was negative. The recovery was smooth, with a mean postoperative hospital stay of (11.4±3.4) days. Pathological examination revealed 15 cases of R.E.N.A.L. carcinoma, 2 angiomyolipoma, and 2 others. All the patients were alive after a mean follow-up of (13.1±6.7) months, without local recurrence or distant metastasis. Nevertheless, the eGFR was significantly decreased from (104.8±24.0) to (90.4±17.0) mL/(min·1.73 m²) after operation (Z=-3.099, P=0.002). Conclusion Retroperitoneal laparoscopic-assisted mini-incision partial nephrectomy is a safe, feasible and effective alternative for surgical management of complex localized R.E.N.A.L. tumors. It has the combined advantages of open operation and conventional laparoscopic partial nephrectomy, with less surgical demanding and lower cost, and is therefore deserve further popularization.