Purpose To investigate prevalence and predictors of renal function variation in a multicenter cohort treated with radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). Methods Patients from 17 tertiary centers were included. Renal function variation was evaluated at postoperative day (POD)—1, 6 and 12 months. Timepoints differences were Δ1 = POD-1 eGFR − baseline eGFR; Δ2 = 6 months eGFR − POD-1 eGFR; Δ3 = 12 months eGFR − 6 months eGFR. We defined POD-1 acute kidney injury (AKI) as an increase in serum creatinine by ≥ 0.3 mg/dl or a 1.5 1.9-fold from baseline. Additionally, a cutoff of 60 ml/min in eGFR was considered to define renal function decline at 6 and 12 months. Logistic regression (LR) and linear mixed (LM) models were used to evaluate the association between clinical factors and eGFR decline and their interaction with follow-up. Results A total of 576 were included, of these 409(71.0%) and 403(70.0%) had an eGFR p p = 0.003), POD-1 AKI (OR 2.88, p p p p = 0.007), POD-1 AKI (OR 1.83, p = 0.02), and preoperative eGFR p p = 0.019), hydronephrosis (p p p = 0.001) influenced renal function variation (ß 9.2 ± 0.7, p Conclusion Age, preoperative eGFR and POD-1 AKI are independent predictors of 6 and 12 months renal function decline after RNU for UTUC.