Magnetic resonance guided high intensity focused ultrasound (MRgFUS) can be used for focal therapy of prostate cancer. After treatment, these men remain in active surveillance. Effective monitoring of these men requires an understanding of the expected MRI appearance of the prostate after MRgFUS. Twenty-three patients treated with MRgFUS for focal, intermediate risk MR imaging-visible prostate cancer were followed with serial MRI for 6-24 months. We describe temporal changes in the qualitative and quantitative multiparametric imaging features of the prostate gland post-MRgFUS ablation to aid radiologists to better interpret follow-up examinations to detect residual or new disease.