Background Numerous efforts were made to improve renal function and oncologic outcomes in surgery for patients with kidney cancer. We explored new robotic methods in solitary kidneys. Materials and Methods We prospectively registered and included 16 patients in the 3D-robot-assisted partial nephrectomy (RAPN) group with a solitary kidney (anatomic or functional), and retrospectively identified 25 patients with a solitary kidney who received RAPN also operated by us for comparison. Results The rates of global clamping reduced in the 3D-RAPN group (37.5% vs 76%)while selective rates were higher (56.2% vs 20%) (p = 0.028). The mean percentages of Scr increase (+20.2% vs +30.2%, p = 0.045) and eGFR reduction (-16.8% vs -27.1%) as well as rate of opening collecting systems (31.3% vs 72%, p = 0.010) were lower in 3D-RAPN group. Conclusions 3D-RAPN less impaired the renal function of patients with a solitary kidney and showed superiority or non-inferiority in other evaluation indexes compared to conventional RAPN.