With the progress of the hemodialysis technology, most of the patients with end-stage renal disease can receive long-term regular hemodialysis treatment. The number of patients receiving hemodialysis who develop malignancy is getting increasingly large, because of oxidative stress, the interference of the immune system, virus infection, cytotoxic agents, certain kidney diseases such as acquired polycystic kidney disease, malnutrition, and changes of the DNA repair system. On the other hand, kidney diseases and even chronic renal failure can be secondary to cancer. Thus, hemodialysis for chronic renal failure can be a risk factor for malignancy, and vice versa. Therefore, it is necessary for oncologists and nephrologists to share their experience in treatment and prognostic evaluation of these patients.