Delayed platelet recovery following autologous PBPCs transplantation after myeloablative therapy remains an unresolved problem in lymphoma patients heavily pretreated with several chemotherapy cycles and/or radiotherapy. In the present study of 50 lymphoma patients, the factors influencing platelet recovery after myeloablative therapy followed by autologous PBPCs transplantation were analysed retrospectively. The median age was 42 years (range, 15-58). Fourteen patients had HD and 36 had NHL (13 high-grade and 23 low-grade); most (80%) had stage III or IV. Twenty-two patients had received radiotherapy to various extents before mobilization. The mean number of previous chemotherapy cycles was seven (range 3-24) of different regimens (range 1-4). A median of three leukapheresis procedures (range 1-5) was performed after G-CSF mobilization. Single leukapheresis was sufficient in only one patient. A significant correlation was found between the BFU-E content of autografts and platelet recovery after transplantation. Neither the patient's age and sex nor the stage and grade of lymphoma had any effect on platelet recovery after transplantation. Neither the type of myeloablative therapy used or the dose of G-CSF administered after transplantation had any effect on platelet recovery after transplantation. The type of previous chemotherapy cycles was a major adverse factor affecting the progenitor cell yield in the autografts. Lymphoma patients previously treated with ASHAP and/or Dexa-BEAM cycles had less progenitor cell yield. The chemotherapeutic agents used in previous cycles also had a clear adverse effect on the progenitor cell yield in the autografts. Lymphoma patients previously treated with cycles including cytarabine and/or cisplatin showed significantly less progenitor cell yield and slower platelet recovery after transplantation. All seven patients with delayed platelet recovery had received cytarabine and/or cisplatin in several previous ASHAP and/or Dexa-BEAM cycles. All seven patients had a BFU-E count of less than 1 x 10(5)/kg yield in the autografts.