Data regarding the role of positron emission tomography/computed tomography (PET/CT) to stage lymph nodes in patients receiving neoadjuvant immunotherapy before radical cystectomy are lacking. The aim of this study is to evaluate the role of PET/CT to predict the pathologic lymph node involvement (LNI) in patients with MIBC receiving neoadjuvant pembrolizumab within the PURE-01 trial (NCT02736266).