Infectious disease is the second leading cause of death among dialysis patients, and it is generally assumed that the mortality rate of infectious disease is considerably higher in dialysis patients than in the general population. There are no comprehensive studies on this issue and on the contribution of each category of infectious disease to excess mortality in dialysis patients in Japan. We used mortality data reported to the Japanese Society for Dialysis Therapy and national Vital Statistics data for 2008 and 2009. We calculated standardized mortality ratios and compared the mortality rates for each category of infectious disease. During the 2-year study period, 274,683 and 10,435 deaths from infectious diseases were recorded in 126 million people and 273,237 dialysis patients, respectively. The standardized mortality ratio for all infectious diseases was 7.5 (95% confidence interval, 7.3-7.6) in dialysis patients with respect to the general population in Japan. The categories of infectious disease with a significantly higher standardized mortality ratio among the dialysis patients were sepsis, peritonitis, influenza, tuberculosis, and pneumonia and in that order. In particular, the mortality rate of sepsis contributed to 69.5% of the difference in infectious disease mortality between dialysis patients and the general population. This study underlines markedly increased mortality from infectious diseases, particularly from sepsis, in dialysis patients compared with the general population.