Purpose:VERDICT (Vascular, Extracellular, Restricted Diffusion for Cytometry in Tumours) MRI is a multib-value, variable diffusion time DWI sequence that allows generation of ADC maps from differentb-value and diffusion time combinations. The aim was to assess precision of prostate ADC measurements from varyingb-value combinations using VERDICT and determine which protocol provides the most repeatable ADC.Materials and Methods:Forty-one men (median age: 67.7 years) from a prior prospective VERDICT study (April 2016–October 2017) were analysed retrospectively. Men who were suspected of prostate cancer and scanned twice using VERDICT were included. ADC maps were formed using 5b-value combinations and the within-subject standard deviations (wSD) were calculated per ADC map. Three anatomical locations were analysed per subject: normal TZ (transition zone), normal PZ (peripheral zone), and index lesions. Repeated measures ANOVAs showed whichb-value range had the lowest wSD, Spearman correlation and generalized linear model regression analysis determined whether wSD was related to ADC magnitude and ROI size.Results:The mean lesion ADC forb0b1500had the lowest wSD in most zones (0.18–0.58x10−4mm2/s). The wSD was unaffected by ADC magnitude (Lesion:p= 0.064, TZ:p= 0.368, PZ:p= 0.072) and lesion Likert score (p= 0.95). wSD showed a decrease with ROI size pooled over zones (p= 0.019, adjusted regression coefficient = −1.6x10−3, larger ROIs for TZ versus PZ versus lesions). ADC maps formed with a maximumb-value of 500 s/mm2had the largest wSDs (1.90–10.24x10−4mm2/s).Conclusion:ADC maps generated fromb0b1500have better repeatability in normal TZ, normal PZ, and index lesions.