BACKGROUND: Loss of a child to malignancy is associated with long-term morbidity among surviving parents. This study aims to identify particular sources of stress among parents of children with severe malignancy. METHODS: We attempted to contact all parents in Sweden who lost a child to cancer between 1992 and 1997. Some 449 parents answered an anonymous questionnaire, including a question regarding whether they ever thought that death would be best for the child with severe malignancy. RESULTS: Mothers whose children were unable to communicate during their last week of life were more likely to think that death would be best for the child (relative risk (RR): 1.6; 95% confidence interval (CI): 1.2-2.1). Fathers whose children faced six years or more with malignancy were more likely to think that death would be best for their child (RR: 2.1; 95% CI: 1.3-3.5). CONCLUSIONS: The inability of the child with severe malignancy to communicate increases the likelihood of mothers thinking that death would be best for the child, while longer duration of the child’s illness increases the occurrence of this thought among fathers.