The mitomycins are antitumor antibiotics that are under investigation now for more than 30 years. Mitomycin C (MMC) is the best investigated subtype. It serves as a prototype for drugs with bioreductive alkylation, which is a unique feature of this class. MMC is mainly active under anaerobic circumstances. The pharmacokinetics are linear in a two-compartment model. The main toxicities of MMC are thrombocytopenia and leucocytopenia. Rare but severe side effects are a hemolytic uremic syndrome, pneumonitis and cardiac failure. MMC has a wide clinical antitumor spectrum with efficacy in various tumor types such as gastric cancer, pancreatic cancer, breast cancer, non-small cell lung cancer, cervical cancer, prostate cancer and bladder cancer. Still, the above mentioned side effects prevent a more widespread use. The most important features of the drug will be reviewed.