Background: We have previously shown the prognostic value of three tumor markers (TMs) including Carbohydrate Antigen 125 (CA-125), Carbohydrate Antigen 19-9 (CA 19-9) and Carcinoembryonic Antigen (CEA) in muscle invasive bladder cancer (MIBC). Current report presents an update on TM levels before and after neoadjuvant chemotherapy (NAC) and their association with oncological outcomes. Methods: Serum levels of three TMs were prospectively measured in patients with MIBC who underwent NAC between 2011 and 2019. Rate of pathological upstaging (Path-U) and recurrence-free (RFS) was compared between patients with: (1) Elevated versus normal pre-NAC TM (2) Elevated versus normal post-NAC TM, and (3) Elevated pre-NAC TMs with normalized post-NAC TMs (TM responders) versus persistently elevated post-NAC TMs (TM non responders). Results: Of a total of 199 patients, 63 patients had both pre- and post-NAC TMs. 33/63 (52%) patients had elevated pre-NAC TM of whom, 15/33 (45%) were TM responders. Patients with elevated pre-NAC TM had significantly higher rate of Path-U compared to those with normal pre-NAC TM (62% vs. 22.5%, respectively; P < 0.001). There was no significant difference in Path-U in the other two comparison groups. Patients with elevated pre- and post-NAC TM had significantly lower RFS. Compared to TM responders, TM non responders had significantly higher rate of recurrence (70% vs 34%) and shorter median time to recurrence (4.2 months vs 13.5 months) (P = 0.03). In six patients with recurrence who had complete post cystectomy TM, TM recurrence preceded clinical recurrence by median of 1.2 months (IQR 0.8 – 2.4 months). Conclusions: Elevated TM prior to NAC is associated with pathologic upstaging. TM elevation pre- or post-NAC predicts a worse outcome. Post-cystectomy TM might play a role in earlier detection of recurrence.