The question of what came first—in this case the diagnosis of prostate cancer or its therapy—seems absurd at first glance and is reminiscent of the classic metaphor-like problem that preoccupied the Greek writer Plutarch (45–125). Today it is a matter of course that a reliable diagnosis is made before treating a disease, but this must be viewed as inconsistent in medical history. The beginnings of radical prostatectomy for the treatment of prostate cancer, like the first surgical therapies for kidney and bladder tumors, can be located in the pioneering period of organ surgery in the German Empire (1871–1918). The establishment of this procedure in its current form with larger numbers of cases is in turn thanks to the Nestor of American urology, Hugh Hampton Young, who carried out the first perineal prostatovesiculectomy, which from today’s perspective can be described as complete. Although the indication has remained largely unchanged since then, this intervention has undergone extensive changes in recent decades. But how has the diagnosis of prostate cancer developed in this period? Of course, much more dynamic. While the procedure prostatovesiculectomy was already established, development of prostate cancer diagnosis began first slowly in the course of the 20th century, then more dynamically. The following article uses medical (historical) original sources to present not only the basics and further developments of the established and, at the same time, subject to constant intervention in urology, but also the essential developments in the environment of neighboring medical disciplines, for example, think of laboratory medicine, radiology, nuclear medicine or rehabilitation medicine, but especially pathology. Incidentally, it was only these developments that created the basis for the correct setting of indications and the identification of alternatives to radical prostatovesiculectomy. © 2020, Springer Medizin Verlag GmbH, ein Teil von Springer Nature.