Genetic testing for prostate cancer (PC) is becoming more widely used in the clinical routine, primarily due to the introduction of PARP inhibitors targeting genetically affected patients in their BRCA1/2 and other homologous recombination repair (HRR) genes. Simultaneously, the number of available therapies that are specifically targeting genetically defined PC subgroups is steadily increasing. As a result, the selection of treatment for PC patients is likely to require testing of multiple genes to enable more specific treatment sequences that consider the genetic characteristics of the tumor. Some of the mutations discovered by genetic testing may be hereditary, necessitating the use of germline testing from normal tissue, which is only permitted within the framework of clinical counseling. This change in PC care requires the collaboration by multiple specialists, including experts in molecular pathology, bioinformatics, biology, and genetic counseling. In this review, we aim to provide an overview on the currently relevant genetic alterations in PC for therapeutic purposes and their implications for familial testing.