Electronic symptom monitoring via patient-reported outcome in surgical oncology is limited owing to lengthy instruments and non-specific items in common patient-reported outcome instruments. To establish electronic symptom monitoring through a clinically relevant and fit-for-purpose core set of patient-reported outcome in patients undergoing lung cancer surgery.One qualitative (Cohort 1) and two prospective studies (Cohorts 2 and 3) were conducted between 2018 and 2023. Patients undergoing lung cancer surgery were recruited. Items of symptoms and daily functioning were generated through extensive interviews in Cohort 1 and incorporated into a smartphone-based platform to establish the electronic Perioperative Symptom Assessment for Lung surgery (ePSA-Lung). This tool was finalized and validated in Cohort 2. Patients in Cohort 3 were longitudinally monitored for the first year post-surgery using the validated ePSA-Lung.In total, 1,037 patients scheduled for lung cancer surgery were recruited. The 11-item draft PSA-Lung was generated based on qualitative interview with 39 patients and input from a Delphi study involving 42 experts. A 9-item ePSA-Lung was finalized by assessing 223 patients in the validation cohort; the results supported the instrument's understandability, reliability, sensitivity, and surgical specificity. In Cohort 3 (n=775), compliance ranged from 63.21% to 84.76% during the one-year follow-up after discharge. Coughing, shortness of breath, and disturbed sleep were the most severe symptoms after discharge. Longitudinally, patients who underwent single-port video-assisted thoracic surgery had a lower symptom burden than those who underwent multi-port video-assisted thoracic surgery or thoracotomy (all symptoms, P<0.001).The ePSA-Lung is valid, concise, and clinically applicable as it supports electronic symptom monitoring in surgical oncology care. The need for long-term extensive care was identified for patients after discharge, even in early-stage cancer with potential curative treatment.Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.