Medical and demographic variables were examined as predictors of acute health-related quality of life (HRQL), specifically, somatic distress, mood disturbance and activity levels, during the period of bone marrow transplant (BMT) hospitalization, and the transition phase in the months following hospital discharge. The responses of 153 children undergoing BMT were assessed by both parent report and patient self-report in a prospective longitudinal design. Type of transplant, diagnosis, age, gender, and socio-economic status (SES) were examined as predictor variables of patient outcome. Type of transplant, patient age, and SES emerged as significant determinants of patient response. Children undergoing unrelated donor (MUD) transplants experiencing the highest levels of distress, followed by those undergoing matched-sibling BMT, while those undergoing autologous transplant experienced the lowest levels of distress. Younger patients experienced lower levels of distress and better HRQL than older children and adolescents. Although patients from different SES backgrounds appeared very similar at the time of hospital admission, those from lower SES backgrounds demonstrated greater distress and disturbance in HRQL subsequently, and throughout the first 6 months post BMT. These findings help to target specific subgroups of patients that may be in greater need of preventive interventions or more aggressive supportive care.