The overall aim of the present thesis is to attain a better insight into different psychological aspects related to anesthesia in children. The specific aims include: firstly, the examination of associations between pre-existing emotional/behavioral problems in children and children’s specific peri- and postoperative behaviors, including anxiety during induction, emergence delirium, changes in sensory processing and pain at home; secondly, the exploration of the validity of a new, easy-to-use anxiety assessment tool at induction of anesthesia; thirdly, the assessment of the usefulness of an audio-visual tool for decreasing parental anxiety at induction of anesthesia of their child.