Parents experience anxiety and concern about their children's anesthesia and surgeries, which can adversely affect the children's outcomes. Therefore, it is important to identify the factors that influence parental fear. Because dermatological surgery is often performed in young children, we examined how a child's age and the size of the dermatological surgical area affected the levels of parental anxiety and concern. The parents' levels of anxiety and concern were accessed by parental self-reports in a prospective observational study of 106 children undergoing dermatological surgery. Correlation analysis showed that the level of parental anxiety decreased with the child's age. In contrast, the level of parental anxiety increased with the size of the surgical area. Our findings thus indicate that parents whose children undergo large-sized surgeries at a young age are at high risk. This result should be considered when performing dermatological surgery in children.