Background: Pathologic progression is identified in > 25% of prostate cancer (CaP) patients on active surveillance (AS). Yet, identifying patients at risk for progression is limited to PSA based biomarkers with variable utility. Multiparametric MRI (mpMRI) with fusion-guided prostate biopsy (FBx) has shown utility in risk stratification for patients considering AS. We compared mpMRI characteristics with PSA kinetics for the prediction of pathologic progression in AS patients. Methods: A review of men on AS with serial mpMRI and 2 or more FBx sessions was performed. FBx sessions consisted of targeted biopsies and a 12 core systematic biopsy. Men who met NIH Expanded AS criteria included those with low and intermediate risk CaP, Gleason score ≤ 3+4 = 7 with no restriction on percent core involvement or number of cores positive. Progression was defined by patients with initial Gleason 3+3 = 6 to any Gleason 4, and Gleason 3+4 = 7 to a primary Gleason 4 or higher. MRI progression was defined as increase in suspicion score, size, or new lesion on follow-up. PSA velocity (PSAV) > 0.75ng/ml/yr, PSA doubling time (PSAdt) < 3 yrs, and imaging characteristics were examined for association with pathologic progression at surveillance biopsy. Results: A total of 164 men, median age of 63 yrs [58-67], were included. Median length of follow up was 19.4 months [IQR 14.3-30.0]. Median PSA, and prostate volume of our cohort were 4.9ng/ml [3.3-7.3] and 47.0ml [36.5-59.8]. The sensitivity and specificity of predicting pathologic progression by mpMRI, PSAV and PSAdt were 45% and 65%, 30% and 76%, and 17% and 86% respectively. A combination of MRI, and PSAV or PSAdt yielded a sensitivity and specificity of 61% and 49% or 54% and 56% respectively. Using a decision curve analysis, mpMRI offers minimal benefit for predicting pathologic progression of CaP. Conclusions: MpMRI alone marginally outperforms PSA kinetics for predicting pathologic progression in men on AS for CaP. The combination of mpMRI along with PSA parameters increase the sensitivity of prostate imaging in identifying progression in AS patients. Research in combinations of imaging with other biomarkers will be needed to more accurately risk stratify AS patients.