Background: To assess the effect of introducing a protocol for single dose of intravesical mitomycin-C (MMC) given in theatre immediately after transurethral resection of bladder tumor (TURBT) on the recurrence rate of non muscle-invasive bladder cancer. Patients and Methods: The recurrence rates of bladder cancer in patients undergoing TURBT only and following the introduction of a protocol for instillation of MMC in theatre after TURBT were calculated. Patients with muscle-invasive disease and those requiring further intravesical treatment were excluded from analysis. Results: In patients undergoing TURBT only, 55.9% had recurrence with a median follow-up of 20.4 months. Following the introduction of a protocol for instillation of MMC in theatre, 37.5% of patients had a recurrence with a median follow-up of 16 months. Recurrence rates were higher for T1, multifocal tumors and recurrent tumors. There were 2 minor complications following instillation of MMC in theatre. Conclusion: A single immediate instillation of MMC in theatre following TURBT is simple and safe. It reduces tumor recurrences and should be considered following TURBT. However, patients with multiple or T1 bladder tumors will still benefit from additional intravesical therapy.