Dynamic contrast-enhanced MRI (DCE-MRI) has proven to be an effective method for qualitative and quantitative measurement of synovitis in the knee. Here we evaluate the test-retest repeatability of DCE-MRI measurements in the knee at 3 T. Eight patients with mild/moderate knee osteoarthritis (OA) were scanned twice, 4 weeks apart. DCE biomarkers from the extended Tofts model were measured. This is the first demonstration of the repeatability of DCE-MRI in knee OA. This evaluation provides data to enable sample size calculations for further longitudinal and interventional studies using DCE-MRI as a biomarker of inflammation in OA.