OBJECTIVE: The aim of our study is to discuss the efficacy of low-density lipoprotein-cholesterol (LDL-C) apheresis procedure using the cascade filtration system for pediatric patients with homozygous familial hypercholesterolemia (FH), and to clarify the adverse effects and difficulties. METHODS: LDL apheresis using the cascade filtration system was performed in 3 pediatric patients with homozygous FH. In total, 120 apheresis sessions were performed for all patients. RESULTS: Cascade filtration therapy significantly reduced the mean LDL-C values from 418 ± 62 mg/dl to 145 ± 43 mg/dl (p<0.05). We determined an acute mean reduction in the plasma levels of total cholesterol (57.9%), LDL cholesterol (70.8%), and high-density lipoprotein (HDL) cholesterol (40.7%). Treatments were well tolerated. The most frequent clinical adverse effects were hypotension in 3 sessions (2.5%), chills/feeling cold (1.7%) in 2 sessions, and nausea and vomiting in 3 sessions (2.5%). CONCLUSION: Our experience with three patients using the cascade filtration system were, good clinical outcomes, laboratory findings, safety of usage, minor adverse effects and technical problems.