In recent years the scientific literature in the field of the prostate carcinoma (PCa) pointed out on the genetic heterogeneity and mutations occurring in this tumour, while little attention was given to the causes of PCa onset, in particular infectious agents. In this brief commentary, we wish to point out recent advancements done on the role of the human polyomavirus BK (BKPyV) in the development of PCa by harnessing both humoral and cellular immune responses. Altogether, these new insights suggest that BKPyV is involved in the transforming activity during the multistep process of PCa development. Although these findings do not provide evidence for a causal relationship between BKPyV and PCa development, additional investigations with novel techniques will help to make it a concrete event.