Calyceal diverticulum, also known as pyelogenic cysts, is a relatively uncommon condition, usually asymptomatic and incidentally diagnosed during routine imaging. Sometimes it may lead to concerning symptoms such as hematuria and flank pain, mimicking the presence of a renal tumor. In this case report, the patient suffered from hematuria which was initially suspected to be indicative of a renal malignancy but that was ultimately attributed to a calyceal diverticulum. The reported case gives the opportunity to evaluate one of the rarest and underestimated causes of hematuria and to describe the main imaging features of the calyceal diverticulum. In particular, the following diagnostic imaging methods have been performed: Ultrasound, Computed Tomography Urography, Dual Energy Computed Tomography, and Magnetic Resonance Urography. Subsequently, this case report has also an educative purpose.