Objective To investigate the level of PBMC NF-κB activity, and its influence on expression of interleukin-6 in maintained-hemodialysis (MHD) patients. Methods Thirty-three patients were included in the study, 17 cases received hemodialysis with cellulose diacetate membrane (CDA group) and 16 cases with polysulfone membrane (PS group), for more than 6 months. Fresh isolated PBMC were cultured. IL-6 mRNA were measured with RT-PCR, and activity of NF-κB were measured with eletrophoresis mobility shift assay. Results Cultured with medium or lipopolysaccharide, the level of PBMC NF-κB activity, gene expression and protein synthesis of PBMC IL-6 in PS and CDA group were significantly increased when compared with those in healthy and non-hemodialysis group (P<0.05). Pyrrolidinedithiocarbamate could not only significantly inhibit the activity of NF-κB, but also inhibit the expression of IL-6 in PBMC (P<0.01). The level of in NF-κB activity PBMC correlated with gene expression and protein synthesis of IL-6 in PBMC (P<0.05). Conclusion We suggest that the level of PBMC NF-κB activity is increased, and NF-κB may mediate IL-6 up-expression in MHD patients.