We present the first case of a patient with a retained ureteric stent subsequently presenting with upper tract urothelial carcinoma (UTUC). A 43-year-old male, who was lost to follow-up after stent insertion for ureteric stones in 2016, presented with haematuria and weight loss. Imaging revealed a renal mass, retroperitoneal lymphadenopathy and a retained ureteric stent. Radical nephroureterectomy and retroperitoneal lymph node dissection confirmed UTUC with squamous differentiation. This case demonstrates a potential relationship between long-term mechanical irritation in the upper urinary tract and UTUC, but given the absence of prior reports, highlights the need for further investigation into chronic irritation as a risk factor for UTUC.