Background: Preoperative anxiety and depression are predominant risk factors for increased postoperative pain. Thoracic wall deformities in adolescents often cause low self-esteem, which contributes to psychological concerns. Several studies have suggested a relationship between preoperative mental health treatment and enhanced recovery after surgery. Objective: This study investigated the validity of screening questionnaires concerning psychological trait and state characteristics via a patient-specific online platform. Methods: Patients scheduled for elective pectus surgery between June 2017 and August 2017 were invited to participate in clinical interviews and online self-report questionnaires. All patients were recruited in the Anesthesiology Department, Antwerp University Hospital, Belgium. This single-center observational cohort study was performed in accordance with the ethical standards of Good Clinical Practice guidelines (ICH-GCP) and the Declaration of Helsinki after obtaining study approval by the Institutional Review Board and Ethics Committee of the Antwerp University Hospital, Belgium (study identifier: 17/08/082). Patients with a history of a psychiatric disease, chronic opioid use (more than three months) or revision surgery were excluded. A preoperative psychological inventory was performed using the Rosenberg self-esteem scale (RSES), Hospital Anxiety and Depression Scale (HADs) and State-Trait Anxiety Inventory (STAI). The results were postoperatively compared with pain intensity and interference using the Multidisciplinary Pain Inventory (MPI), Coping Pain Questionnaire (CPQ) and numeric pain rating scale assessment (NRS). Results: Of the 22 patients, 21 used our web-based psychological perioperative screening platform. A "success" was reported by 85% of the patients for the smartphone application, 89% for individual online platform usability and 95% for accessibility. A total of 89% of the patients rated the effort of generating answers to the online questionnaire as low. The results from the completed questionnaires indicated a strong negative correlation between self-esteem and the anxiety trait (R = -0.72, p < 0.01) and overall anxiety characteristics (R = -0.49, p = 0.04). There was a positive correlation between depressive and anxiety characteristics and the anxiety trait (R = 0.52, p = 0.03; R = 0.6, p = 0.02, respectively). Moreover, preoperative anxiety was positively correlated with postoperative pain interference (R = 0.58, p = 0.02). Finally, there was a negative correlation between self-esteem and pain interference (R = -0.62, p = 0.01). Conclusions: Perioperative screening of psychological symptoms and trait characteristics with specific treatment, if necessary, could further improve postoperative pain and overall health status. Research on E-health technology, even for psychological patient care, is rapidly increasing. Trial Registration: ClinicalTrials.gov NCT03100669