To assess the safety and feasibility of early single dose mitomycin-C (MMC) bladder instillation following robot-assisted radical nephroureterectomy (RANU) at a tertiary kidney cancer centre. Radical nephroureterectomy with bladder cuff excision and subsequent mitomycin-C (MMC) bladder instillation to reduce recurrence risk is the gold standard for high risk upper urinary tract urothelial carcinoma (UUTUC).