Muscle-invasive bladder cancer (MIBC) presents a heterogeneous response to perioperative chemotherapy. Although several molecular classifications of MIBC have been proposed, two main subtypes, namely, luminal and basal, are widely recognised. This study aims to explore the relationship between the molecular subtypes of MIBC, as characterised by GATA binding protein 3 (GATA3) and cytokeratin 5/6 (CK5/6) immunohistochemistry, and treatment response to neoadjuvant chemotherapy.