Background. Postoperative surveillance with chest computed tomography (CT) is often performed in patients who have undergone resection of non-small cell lung cancer (NSCLC), despite lack of supporting data. This study involves the creation of a decision analysis model to predict the cost effectiveness of postoperative surveillance CT. Methods. A decision analysis model was created in which a hypothetical cohort of patients underwent annual chest CT after resection of a stage IA NSCLC. The incidence of second primary lung cancer (SPLC), sensitivity and specificity of CT, as well as survival after resection of initial primary and SPLC were derived from published literature. The cost of CT and other procedures prompted by a positive finding on CT was calculated from Medicare reimbursement schedules. Cost effectiveness was defined as a cost of less than $60,000 per quality-adjusted life-year gained in the cohort under surveillance compared with controls under no surveillance. Results. In the initial (base case) analysis, the cost of surveillance CT was $47,676 per quality-adjusted life-year gained, implying cost effectiveness. However, factors that rendered surveillance CT cost ineffective were (1) age at entry into the surveillance program greater than 65 years, (2) cost of CT greater than $700, (3) incidence of SPLC of less than 1.6% per patient per year of follow-up, and (4) a false positive rate of surveillance CT greater than 14%. Conclusions. Surveillance with postoperative CT may be a cost-effective intervention to detect SPLC in selected patients with previously resected stage IA NSCLC.