Objective  To explore the surgical technique of robot-assisted modified retroperitoneal lymph node dissection (LND) in patients with renal pelvic and upper ureteral tumors, and summarize the short-term efficacy.Methods  The clinical data of 22 patients with high-risk renal pelvic and/or upper ureteral tumors who received robot-assisted nephroureterectomy with modified retroperitoneal LND from January 2019 to January 2022 at the first affiliated hospital of Nanjing medical university were retrospectively analyzed. For tumors located on the left side, the left renal hilar, preaortic and paraaortic nodes were dissected. The right renal hilar, precaval, paracaval, retrocaval, and interaortocaval nodes were removed for tumors on the right side.Results  The operative time was (138±14) min. The number of lymph nodes removed was (14.0±4.5), with positive lymph nodes in 18.2% (4/22) patients. During a follow-up of （14.3±6.3）months, two patients experienced intravesical recurrences, and one patient with lymph node metastasis died of lung metastasis.Conclusions  Robot-assisted retroperitoneal LND is safe and feasible, with satisfied exposure of the hilar, retrocaval and interaortocaval nodes.