Paediatric surgery elicits anxiety in children and their parents. The present study tests the impact of Play Specialist-based intervention (PS) on children’s and parents’ anxiety pre and post thoracoplasty. The study was held at Gaslini pediatric hospital (Genoa, Italy) and involved families with a child undergoing thoracoplasty to correct childrenʼs pectus carinatum (PC) or excavatum (PE). Children provided with PS-based intervention (n=40) were compared with control children (n=32). The mothers of PS children (n=40) were compared with the control mothers (n=32), and the fathers of PS children (n=40) were compared with the control fathers (n=32). Visual Analog Scale (VAS) was administered to assess pre and post thoracoplasty anxiety. T-tests and Analyses of Covariance (ANCOVA), Bayes factors for t-tests and ANCOVA were computed. A significant interaction effect between time and group (i.e., PS and controls) emerged for children, mothers, and fathers. Bonferroni post-hoc analyses revealed that PS children’s and PS mothers’ postoperative anxiety was lower than controls’ postoperative anxiety. PS fathers’ experienced greater preoperative anxiety than controls and no significant differences with control fathers emerged in postoperative anxiety. PS-based intervention emerged to reduce children’s and parents’ anxiety over time, and to diminish children’s and mothers’ postoperative anxiety in comparison with the controls.