We performed 29 large-volume leukaphereses of 20 patients for collection of peripheral blood stem cells. All patients have been pretreated with cytokines after chemotherapy. In 9 patients with precounts of > or = 3 x 10(9) mononuclear cells/l we achieved a sufficient transplantation doses with one LVL. If the MNC precount was < or = 3 x 10(9)/l we had to perform more than one LVL. On 16 patients we compared a standard apheresis procedure with the LVL procedure. It seems that especially patients with a lower MNC precount can profit from LVL. From patients with higher MNC precounts we harvested the double amount of MNCs, from patients with lower MNC precounts the triple amount.