Two hundred and seventy-seven consecutive patients with non-Hodgkin's lymphoma (n = 207), Hodgkin's disease (n = 27) and multiple myeloma (n = 43) were intensified from October 1989 until April 1997 and received unmanipulated PBPC transplants. Twenty-three patients received a double intensification, out of a total of 300 PBPC transplantations analyzed. Conditioning regimens consisted of total body irradiation (TBI)-containing regimens (n = 141), BEAM (n = 104), high-dose melphalan (n = 26), ICE (n = 23) or other regimens (n = 6). Eighty-four percent of the patients (119/142) evaluable for long-term hematological reconstitution beyond 180 days achieved normal trilineage blood counts. Abnormal hematological parameters were associated with low numbers of CD34+ cells re-infused and with prior exposure to fludarabine. The 100-day and long-term treatment-related mortality rates were 4% and 4%, respectively. Late complications and treatment-related toxicities were influenced by disease history, use of TBI and exposure to fludarabine. Patients older than 60 years did not have greater toxicities or more frequent treatment-related deaths. This analysis suggests that while leading to a limited morbidity and a low mortality rate, intensive chemotherapy with PBPC transplantation still remains a procedure leading to significant short- and long-term toxicities. Better recognition of the risk factors associated with these complications might allow a further decrease in their incidence.