Most of the previous studies on immune dysregulation in end-stage renal disease (ESRD) have focused on T cell immunity. We investigated B cell subpopulations in ESRD patients and the effect of hemodialysis (HD) on B cell-associated immune profiles in these patients. Forty-four ESRD [maintenance HD patients (n = 27) and pre-dialysis patients (n = 17)] and 27 healthy volunteers were included in this study. We determined the percentage of B cell subtypes, such as mature and immature B cells, memory B cells, and interleukin (IL)-10+ cells, as well as B cell-producing cytokines (IL-10, IL-4 and IL-21) by florescent activated cell sorting (FACS). B cell-associated gene expression was examined using real-time PCR and B cell producing cytokines (IL-10, IL-4 and IL-21) were determined using an enzyme- linked immunosorbent assay (ELISA). The percentage of total B cells and mature B cells did not differ significantly among the three groups. The percentages of memory B cells were significantly higher in the pre-dialysis group than in the HD group (P < 0.01), but the percentage of immature B cells was significantly lower in the pre-dialysis group than in the other groups. The percentages of IL-10-expressing cells that were CD19+ or immature B cells did not differ significantly (P > 0.05) between the two subgroups within the ESRD group, but the serum IL-10 concentration was significantly lower in the pre-dialysis group (P < 0.01). The results of this study demonstrate significantly altered B cell-associated immunity. Specifically, an imbalance of immature and memory B cells in ESRD patients was observed, with this finding predominating in pre-dialysis patients.