Throughout history, medicine has witnessed paradigm shifts that significantly change patient treatment. In surgical oncology, the introduction of lumpectomy revolutionized breast cancer treatment while partial nephrectomy has altered the management of kidney cancer. In both cases, organ preservation is combined with efficacious management of the cancer via a less invasive approach. Within urology, prostate cancer (PCa) may be the next to benefit from such a treatment paradigm. Current management of PCa involves either whole organ treatment, with the inherent side effects, while selected patients are eligible for active surveillance. Focal therapy offers a middle ground for low-risk patients with PCa, again using the principles of a minimally invasive treatment of the cancer, in this case using an energy source with few side effects, combined with maximal organ preservation. Because focal therapy for PCa is still in evolution, there is no consensus on the ideal energy source that should be used to ablate the PCa, imaging to monitor the tissue destruction in real time, how many treatments may be offered, and the ideal follow-up regimen. Long-term follow-up of patients is needed before it is recommended as a first-line treatment. Nevertheless, evidence is accumulating that radically treating PCa holds survival benefit for patients; however, the number of men needed to treat is considerable, with significant side effects; thus, more centers are investigating focal therapy as an option. This review focuses on the use of the laser as the energy source for focal ablation, while bringing historically relevant information regarding laser energy and highlighting the perceived advantageous of focal laser ablation.