Background: Improved survival in children with critical illnesses has led to new disease patterns. As a consequence evaluation of the well being of survivors of Pediatric Intensive Care Units (PICU) has become important. Outcome assessment should therefore consist of evaluation of morbidity, functional health and Health Related Quality of Life (HRQoL). Awareness of HRQoL consequences and physical sequelae could lead to changes in support during the acute phase and thereafter. The aim of this study was to evaluate HRQoL in PICU survivors. Methods: Prospective follow-up study three and nine months after discharge from a 14-bed tertiary PICU. Eighty-one of 142 eligible, previously healthy children were included from December 2002 through October 2005. HRQoL was assessed with the TNO-AZL Preschool Children Quality of Life Questionnaire (TAPQOL-PF) for children aged 1 to 6 years of age, the TNO-AZL Children's Quality of Life Questionnaire Parent Form (TACQOL-PF) for children aged 6 to 12 years of age, and the TNO-AZL Children's Quality of Life Questionnaire Child Form (TACQOL-CF) for children aged 8 to 15 years of age. The studied patients were compared with age appropriate normative data using non-parametric tests and effect sizes. Results: Thirty-one and 27 children, and 55 and 50 parents completed questionnaires respectively three and nine months after discharge. In 1-6 year old children parents reported more lung problems (3 and 9 months), worse liveliness (9 months) and better appetite and problem behaviour (3 months); in 6-12 year old children parents reported worse motor functioning (3 months); and 12-15 year old adolescents reported worse motor functioning (3 months). Large effect sizes indicating clinical significant differences in HRQoL with healthy control subjects were found on more domains. Conclusion: In this small group of PICU survivors differences in HRQoL with the normative population exist three and nine months after discharge. Calculated effect sizes were smaller nine months after discharge. These changes suggest that HRQoL improves over time. More research is necessary but we believe that HRQoL assessment should be incorporated in follow-up programs of PICU survivors.