This paper explored the role of multiparametric MRI (mpMRI) in predicting the likelihood of lymph node invasion in patients with a risk of <5% according to the Briganti nomogram. Three hundred and ten patients who underwent a preoperative mpMRI and subsequent robot-assisted extended pelvic lymph node dissection were retrospectively evaluated. Of these, 60 patients were calculated to have a <5% risk of lymph node invasion according to the Briganti nomogram but adverse mpMRI characteristics (extracapsular extension, seminal vesical invasion or predominant Gleason pattern 4). Nine out of sixty (15%) were found to have positive nodes. All three mpMRI parameters were found to be significant independent predictors of lymph node invasion. Prostatectomists should consider these adverse imaging characteristics in deciding whether patients whose risk is calculated at <5% according to the Briganti nomogram should undergo an extended pelvic lymph node dissection or not.