We hypothesized that the use of hemofiltration (HF) to reduce cytokines may attenuate the hyperbilirubinemia that often develops after left ventricular assist system (LVAS) implantation. Four patients with hyperbilirubinemia after LVAS implantation underwent HF continuously for 7 days. Blood samples were collected and the serum concentrations of total bilirubin (T-Bil), interleukin (IL)-6, and IL-8 were measured. We also measured the serum concentrations of IL-6 and IL-8 in the blood flowing into and out of the filter. Two patients had reduced serum concentrations of IL-6, IL-8, and T-Bil, but the other two did not, despite the effective filtration of these cytokines. Our findings suggest that the reduction of cytokines by HF may assist in the treatment of hyperbilirubinemia after LVAS placement in some patients.