Metabolic syndrome (MetS) contributes to lower urinary tract symptoms (LUTS). However, non-invasive methods for studying this association are limited. This study investigated the relationship of MetS, LUTS, anatomy, and function of the bladder and prostate in men and women. Manual segmentation with 3D rendering of the bladder and prostate were performed from MRI. We found that MetS is associated with increased bladder wall volume and postvoid residual in men but not women, suggesting that the effect of MetS on the prostate contributes to anatomic and functional changes of the bladder in men.