Purpose To describe clinical technique of laser ablation of prostate cancer using MRI guidance as well as ultrasound guidance. To show feasibility in phantoms of using a novel fusion guided platform to ablate prostate cancer using real time ultrasound guidance fused to pre-procedural multi-parametric MRI. Materials and Methods Water cooled laser ablation was performed in patients with Gleason 6 or Gleason 7 prostate cancer that was focal and well visualized by MRI. Focal ablation was performed using MRI guidance and MRI thermometry feedback. Laser ablations were performed in prostate phantoms using a custom ultrasound to MRI fusion software platform.Custom phantom materials (CIRS, Norfolk, VA) were used that show ablated regions with CT, ultrasound, and MRI. Results Focal laser ablation was performed safely in 10 patients with prostate cancer using MRI guidance. Follow-up imaging at day one, 6 months, and one year post-ablation was performed. Biopsy was performed in patients one year post-ablation. Ultrasound to MRI fusion was used to guide laser fibers to targets predefined with pre-procedural MRI, without requiring the presence of the MRI gantry. Conclusion Focal prostate laser ablation of image-able prostate cancer may be safely performed in patients undergoing active surveillance or watchful waiting for non-aggressive prostate cancers. MRI + ultrasound fusion guidance may be used to guide laser fibers to targets identified on prior MRI, without requiring the physical presence of the MRI gantry.