Background High-dose chemotherapy supported by autologous stem cell transplantation is an effective treatment for patients with relapsed or refractory non-Hodgkin's lymphomas (NHLs) and fit patients with multiple myeloma (MM). However, failure rates of hematopoietic stem cell mobilization are estimated to be between 5 and 30%, respectively. Thus, we investigated the efficacy of the combination chemotherapy of high-dose methotrexate (MTX) and cytarabine with granulocyte-colony-stimulating factor (G-CSF) as a remobilization method in those who failed a prior mobilization and collection with chemotherapy and G-CSF. Study Design and Methods Mobilization failure was defined as a collection of fewer than 5 × 106 CD34+ cells after three to five apheresis procedures. MTX (3500 mg/m2 in a 120-min infusion) on Day 1 and cytarabine (3000 mg/m2 infusion for 120 min) on Day 4 and Day 5 were followed by G-CSF (10 μg/kg daily). Results A total of eight patients (six NHL and two MM; median age, 55 years) who had failed in prior mobilization with conventional chemotherapy and G-CSF underwent the second mobilization as described in the method. Successful collection of CD34+ cells (> 5 × 106/kg) was achieved in six patients (75%) with three to five apheresis procedures. The total yield of CD34+ cells/kg body weight was 6.28 × 106/kg (median; range, 1.53 × 10 6-10.09 × 106/kg). Conclusions This preliminary result warrants further investigation of high-dose MTX and cytarabine plus G-CSF as a means to remobilize stem cells in those with prior failure to mobilize stem cells with chemotherapy and G-CSF.