Objective To explore the value of 18F-2-deoxy-2-D-glucose (18F-FDG) positron emission tomography/X-ray computed tomography (PET/CT) in evaluating the staging of lung cancer and the curative effect of neoadjuvant chemotherapy. Methods Eighty patients with non-small cell carcinoma treated in the hospital between January 2013 and July 2017 were enrolled in the study. All patients had clear histopathological findings, 18F-FDG PET/CT and CT imaging data before chemotherapy. Referring to the results of histopathological staging before chemotherapy, the coincidence rate was compared between 18F-FDG PET/CT and CT for staging of lung cancer. The 18F-FDG PET/CT was performed at the end of the first cycle of neoadjuvant chemotherapy, and CT was performed at the end of the first and second cycle of neoadjuvant chemotherapy to assess the curative effect of chemotherapy. The differences between the two examination methods for evaluating the curative effect were compared. Results With the pathological results as the golden standard, the coincidence rate of CT in staging of lung cancer was slightly higher than that of 18F-FDG PET/CT (83.75% vs 92.50%) (χ2 =2.926, P=0.087). After the first cycle of chemotherapy, the remission and non-remission rates of metabolism and the objective response rate evaluated by 18F-FDG PET/CT were 57.50%, 42.50% and 57.50%, respectively. The PR, SD and the objective response rate evaluated by CT were 32.50%, 67.50% and 32.50%, respectively (χ2 =15.625, P<0.001). After the second cycle of neoadjuvant chemotherapy, the PR, SD and PD evaluated by CT were 34 cases (42.50%), 38 cases (47.50%) and 8 cases (10.00%), respectively. The objective response rate was 42.50%. There was no significant difference in the objective response rate evaluated by PET/CT after the first cycle of chemotherapy (χ2 =3.60, P>0.05). According to the results of CT in assessment of the curative effect after the second cycle of chemotherapy, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 18F-FDG PET/CT in predicting the curative effect of neoadjuvant chemotherapy for lung cancer were 82.35%, 60.86%, 70.00%, 60.87% and 82.35%, respectively. Conclusion Compared with CT, 18F-FDG PET/CT not only can be used for early clinical staging of lung cancer, but also assessment of the curative effect of early neoadjuvant chemotherapy. However, the threshold value of SUVmax decline in assessment of the curative effect needs further study.