Aim: This study aimed to assess the effectiveness of a storybook, entitled, The Tale of Woody’s Tonsils, written by Anne Marie Tunney, on reducing the level of anxiety of children aged 5–11 years who were undergoing tonsillectomy and adenoidectomy in one hospital in Northern Ireland. Background/Literature Review: Psychological preparation of children for surgery impacts coping. There is evidence, in both adult and pediatric studies, that effective psychological preparation for a surgical procedure has an impact on the individuals’ coping ability with reduced levels of anxiety leading to better post-operative outcome, faster recovery and a reduction in long term sequelae associated with admission to hospital. A storybook, as a method of preparation, has been recommended by a number of researchers but the effectiveness of this in reducing anxiety has not yet been investigated in the UK. Previous studies have mainly used only one research instrument for anxiety measurement and child self-report is not a commonly used feature of such research. Design and Methodology: A quasi-experimental study involving 80 children was conducted using a repeated measures design. Children attending a pre-assessment clinic were randomly allocated to either an experimental group (received the storybook) or a control group (did not get the storybook). Anxiety was tested both pre- and post-intervention using a self-report Hospital Fears Rating Scale and Child Drawing: Hospital, a projective technique based on children’s drawings. Findings: The storybook was found to be effective in reducing pre-operative anxiety and was found to be particularly effective for females and in the 7-year-old age group. Practice Implications; This study demonstrates the storybook’s effectiveness for alleviating anxiety and advocates the use of child focused anxiety measurement tools. It reinforces the need for pre assessment to include exploration of anxiety triggers so that preoperative preparation and nursing care can be individualized for each child.