We report the case of a 53-year-old man suffering from the contemporary onset of penile Mondor's disease and high-flow priapism 10 days after a transrectal prostate biopsy. We analyzed whether these pathological conditions were causally related to the biopsy, and the role of urologist regarding the onset of one or both the diseases. Critically evaluating the clinical picture and the procedure used for the biopsy, we were able to recognize a connection between the office procedure and the onset of the high-flow priapism, otherwise than for penile Mondor's disease. Our report is of value for urologists, making them aware of such possible complications, and for forensic experts that might have to deal with similar cases, as it demonstrates only a partial involvement of urologist in this clinical setting.