Intravesical instillation of mitomycin C after a transurethral resection of a bladder tumor constitutes a standard treatment modality in the management of superficial transitional cell carcinoma in the urinary bladder. An immediate instillation of mitomycin C after transurethral resection has been shown to reduce the recurrence rate of superficial transitional cell carcinoma. Intravesical mitomycin C is generally considered to be a safe treatment option, but the past few years have seen the publication of a number of case reports on severe complications following mitomycin C instillation. This article reports on the mode of action, as well as the intravesical effects and current indications for mitomycin C instillation. This review will summarize the oncological benefits of mitomycin C in comparison with other intravesical treatments, such as bacillus Calmette–Guérin, and elucidate the incidence and types of possible complications associated with intravesical mitomycin C chemotherapy.