 Within a randomized controlled design the effects of a brief two-session psychological intervention child, parents shall be studied in 30 siblings of newly diagnosed pediatric cancer patients. After a baseline assessment 3-4 weeks after diagnosis participants are randomly assigned to an intervention or waiting list group. Both are re-assessed at 3 and 6 months by means of standardized questionnaires assessing psychological adaptation and behavior. The intervention is provided to the waiting list group after the 6-month assessment. 