Squamous cell carcinoma of the renal pelvis is a rare tumor with a poor prognosis, mainly occurring in patients with neglected and secondarily infected pyelocalyceal stones. We report a new case of a 45-year-old man who presented with features of pyonephrosis and was subjected to nephrectomy. Post-operative histological evaluation revealed an unsuspected squamous cell carcinoma of the renal pelvis. The patient died 3 months after the operation. Based on our observation and a review of the literature, we discuss the etiopathogenesis, histological, clinical and therapeutic aspects of this pathology.