The effectiveness of the novel hematopoietic stem cell mobilizing agent plerixafor was evaluated in nationwide compassionate use programs in 13 European countries. A total of 580 poor mobilizers with non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma (HL) and multiple myeloma (MM) were enrolled. All patients received plerixafor plus granulocyte CSF with or without chemotherapy. Overall, the collection yield was significantly higher in MM patients (>2.0 × 10(6) CD34+ cells/kg: 81.6%; >5.0 × 10(6) CD34+ cells/kg: 32.0%) than in NHL patients (>2.0 × 10(6) CD34+ cells/kg: 64.8%; >5.0 × 10(6) CD34+ cells/kg: 12.6%; P<0.0001) and also significantly higher in HL patients (>2.0 × 10(6) CD34+ cells/kg: 81.5%; >5.0 × 10(6) CD34+ cells/kg: 22.2%) than in NHL patients (P=0.013). In a subgroup analysis, there were no significant differences in mobilization success comparing patients with diffuse large B-cell lymphoma, follicular lymphoma and mantle cell lymphoma. Our data emphasize the role of plerixafor in poor mobilizers, but further strategies to improve the apheresis yield especially in patients with NHL are required.