Background/objective: Acute kidney injury (AKI) is a frequent complication of multiple myeloma (MM) with an incidental rate of 20-50% and up to 5% found to have severe AKI that required dialysis. It is most commonly caused by light chain cast nephropathy (LCCN) with a prevalence of 32-57%, particularly when serum free light chains (sFLC) concentration exceeds 500mg/L. Early reduction of sFLC level may promote renal recovery in dialysis-dependent AKI secondary to MM and indirectly improve overall survival rate. High cut-off hemodialysis (HCO-HD) was known to effectively remove the sFLC level in LCCN. However, EULITE and MYRE trials revealed that HCO-HD failed to achieve hemodialysis independence at 3 months. Medium cut-off hemodialysis (MCO-HD) has shown to remove larger middle molecular weight (>25kDa) uremic toxin among patients on maintenance HD, with substantial reduction of free κ and λ light chains (22.5kDa and 45kDa respectively) at 4- and 24-weeks post treatment. Our aim is to describe our experience in using MCO-HD adjunct therapy for patients presented with high sFLC concentrations and dialysis-dependent AKI to promote renal recovery. Methods: 4 MM patients with dialysis-dependent AKI who underwent adjunct MCO-HD treatment with Theranova 400, Polyarylethersulfone, Baxter were studied. We recorded clinical characteristics, biochemical data, treatment methods and follow-up results. Results: MCO-HD was initiated at median duration of 7 days from AKI presentation. The mean involved sFLC prior to MCO-HD initiation was 7505 ± 2980 mg/dL (IQR, 4820-15000). Mean total sFLC were reduced by 75.9 ± 28.4% after a 32.5 days median duration of MCO-HD. Three out of four patients achieved renal recovery for a median duration of nine months. Two patients died from disease relapse. Conclusion: Our study suggests that before definitive chemotherapy, early initiation of MCO-HD can potentially be used as an auxiliary treatment for patients with MM and dialysis-dependent AKI.