PIWI-interacting RNA (piRNA) is a subset of small noncoding RNA with approximately 26-30 nucleotides, and it plays a vital role in maintaining genome stability and modulating protein synthesis. Recently, emerging evidence suggested that piRNA are expressed in a tissue-specific manner across diverse human cancers, intricately modulating pivotal signaling pathways at the transcriptional or post transcriptional level. This review systematically underscores current investigations pertaining to piRNA in urologic carcinoma (UC), elucidating the proposed regulatory mechanisms encompassing N6- methyladenosine (m6A) modification and the silencing of transposable elements. Furthermore, we discussed the detection technology and the application of piRNA in the fields of clinical diagnosis.