In the current study, we investigated the occurrence of posttraumatic growth (PTG) among parents whose children had had stem cell transplantation (SCT) and survived. Although SCT is well established, it remains stressful and dangerous, and SCT is only performed if there is no other choice of treatment to be considered. A questionnaire batteries including the Post-Traumatic Stress Disorder (PTSD) Check List—Civilian version and the Post-Traumatic Growth Inventory were sent out to a cross-sectional national sample of parents of children who had had SCT six months or more before the study. The response rate was 66% (n = 281). The data were analyzed in relation to parents’ appraisal of the event, gender, and perceived social support. The results confirm that SCT in childhood is an event of extreme adversity for the parents. Indications of PTSD were found among an important minority of the parents. Nevertheless, a large proportion of the parents had experienced growth as a consequence of the child’s illness. Appreciation of life and personal strength were the domains with the highest scores. Moreover, a higher level of PTG was correlated with a higher level of posttraumatic stress and with an experience of the trauma as more severe. In summary, the study indicates that PTG is a relevant concept for this group of parents.