BackgroundIn patients with relapsed or refractory B cell acute lymphoblastic leukemia or B cell non‐Hodgkin lymphoma (r/r B‐ALL/B‐NHL) with low CD3+ cells in the peripheral blood (PB), sufficient CD3+ cell yield in a single day may not be obtained with normal‐volume leukapheresis (NVL). Large‐volume leukapheresis (LVL) refers to the processing of more than three times the total blood volume (TBV) in a single session for PB apheresis; however, the efficiency and safety of LVL for manufacturing of tisagenlecleucel (tisa‐cel) remain unclear. This study aimed to investigate the tolerability of LVL.Study Design and MethodsWe retrospectively collected data on LVL (≥3‐fold TBV) and NVL (<3‐fold TBV) performed for patients with r/r B‐ALL/B‐NHL in our institution during November 2019 and September 2023. All procedures were performed using a continuous mononuclear cell collection (cMNC) protocol with the Spectra Optia.ResultsAlthough pre‐apheresis CD3+ cells in the PB were significantly lower in LVL procedures (900 vs. 348/μL, p < .01), all patients could obtain sufficient CD3+ cell yield in a single day with a comparably successful rate of final products (including out‐of‐specification) between the two groups (97.2% vs. 100.0%, p = 1.00). The incidence and severity of citrate toxicity (no patients with grade ≥ 3) during procedures was not significantly different between the two groups (22.2% vs. 26.1%, p = .43) and no patient discontinued leukapheresis due to any complications.ConclusionLVL procedures using Spectra Optia cMNC protocol was well tolerated and did not affect the manufacturing of tisa‐cel.