The advantages of retroperitoneoscopic technique are well known. We decided to combine this access with the emerging laparoendoscopic single-site surgery (LESS) technique. We present our preliminary data on 11 renoureteral procedures and describe our retroperitoneoscopic LESS technique. As of March 2009, 10 patients were submitted to retroperitoneal LESS and divided into three groups: Group A, 3 patients underwent ureterolithotomy; Group B, 4 patients underwent renal cyst ablation; Group C, 4 patients underwent renal biopsy. Retroperitoneal access was obtained with an optical trocar. After retroperitoneal space blunt dissection, a multichannel port was placed. Standard and bent 5-mm instruments were used; we also used a 5-mm flexible laparoscope as a single procedure in group A. Ten of 11 procedures were completed without conversion; a single case in group A was converted to open surgery. Retroperitoneoscopic LESS is a safe and feasible procedure for renal biopsy and renal cyst ablation, with shorter convalescence time, less postoperative pain, and better cosmetic outcomes. LESS ureterolithotomy was more challenging for the lack of triangulation, resulting in a prolonged convalescence period. In addition, bent laparoscopic instruments are not suitable for retroperitoneal space; the multichannel port leaks carbon dioxide due to the flank position. Therefore LESS pelvic trainer practice is imperative in this case.