The Committee of Scientific Academy of the Japanese Society for Dialysis Therapy (JSDT) proposes a new standard on microbiological management of fluids for hemodialysis and related therapies. This standard is within the scope of the International Organization for Standardization (ISO), which is currently under revision. This standard is to be applied to the central dialysis fluid delivery systems (CDDS), which are widely used in Japan. In this standard, microbiological qualities for dialysis water and dialysis fluids are clearly defined by endotoxin level and bacterial count. The qualities of dialysis fluids were classified into three levels: standard, ultrapure, and online prepared substitution fluid. In addition, the therapeutic application of each dialysis fluid is clarified. Since high-performance dialyzers are frequently used in Japan, the standard recommends that ultrapure dialysis fluid be used for all dialysis modalities at all dialysis facilities. It also recommends that the dialysis equipment safety management committee at each facility should validate the microbiological qualities of online prepared substitution fluid.