Segmental (partial) testicular infarction is a very rare condition of unknown cause in more than 70% of cases. Several predisposing conditions have been described, but to our knowledge, this is the first documented case and often overlooked complication occurring as a result of cysto-prostatectomy. It usually presents in an acute manner resembling testicular torsion or epididymo-orchitis and is confirmed using ultrasonography. In some cases, it may present insidiously with no pain and may be confused with a testicular tumor due to the hypo-echoic features on imaging. In unclear situations, Doppler sonography shows vascularity and a magnetic resonance scan can be useful to distinguish between the two conditions.