We have investigated whether hematopoietic stem cell transplantation (HSCT) before the death of children with cancer has a long-term effect on the physical and psychological well-being of the parents. A nationwide questionnaire was sent out to all bereaved parents in Sweden who had lost a child due to a malignancy from 1992 to 1997. Self-reported levels of anxiety, depression and quality of life as well as overall psychological and physical well-being in bereaved parents of children who underwent HSCT were compared with bereaved parents whose children did not receive a transplant. Bereaved parents whose children underwent HSCT had, according to a visual digital scale, an increased relative risk (RR) of long-term anxiety (RR 1.5; 95% confidence interval (CI) 1.0-2.1), poor psychological well-being (RR1.3; 95% CI 1.1-1.5), low quality of life (RR 1.4; 95% CI 1.2-1.7) and poor physical health (RR 1.3; 95% CI 1.1-1.5), whereas the State-Trait Anxiety Inventory and 'The Göteborg Quality of Life Instrument' were non-significantly increased (RR 1.3; 95% CI 0.8-2.3 and RR 1.7; 95% CI 0.9-3.3, respectively). The risks of these consequences were further augmented in case of multiple HSCT. We suggest that bereaved parents of children undergoing HSCT may be at greater risk of decreased psychological well-being than other bereaved parents of children with cancer.Bone Marrow Transplantation advance online publication, 22 November 2010; doi:10.1038/bmt.2010.287.