Reproducible and characteristic clinical findings of fever, skin rash, capillary leak and pulmonary infiltrates have been observed during engraftment in patients with autologous bone marrow (BM) and/or peripheral stem cell transplantation (PSCT). Two hundred and forty-eight patients were analyzed retrospectively to establish the clinical entity, to characterize the clinical course, and to find clinical variables affecting the incidence of the syndrome. One hundred and eight cases (83.7 +/- 9.4%) of fevers occurring in the periengraftment period (PEN) not associated with positive cultures, biopsies, or clinical signs of infection did not reveal delayed documentation of concealed infection in 2 weeks after engraftment. Capillary leak, pulmonary infiltrates, hypoxia, non-infectious neutropenic fever of engraftment and skin rash were found to be interrelated (all P < 0.01 except for hypoxia vs rash; P < 0.05). By stepwise discriminant analysis, one hundred and thirty-two patients (58.9 +/- 6.4%) were shown to have both skin rash and non-infectious neutropenic fever, thereby constituting the syndrome. Sepsis in the first week of neutropenia decreased the incidence of the syndrome (58.5 +/- 7.7% with sepsis, 89.6 +/- 4.7% without sepsis, P < 0.01). Post-transplant granulocyte colony-stimulating factor increased the incidence of the syndrome (79 +/- 4.6% with G-CSF vs 48.3 +/- 8.2% without G-CSF, P < 0.01). In bone marrow transplantation (BMT), the median time of onset of the syndrome was 7 days (range 4-22 days) post-transplant with a median duration of 11 days (range 4-28 days) of the initial phase. Thirty-nine patients (17.4 +/- 5.0%) revealed a recurrent pattern during the 5th week post-transplant.(ABSTRACT TRUNCATED AT 250 WORDS)