Background: The incidence of tumors during pregnancy is 1ntscomprising 0.07-0.1% of all malignant tumors. Lung cancer during pregnancy is rare, but it is the second leading cause of cancer-attributed mortality in women of childbearing age. This article reports 3 cases of lung cancer in pregnant women and reviews the relevant literature, to explore the diagnosis, treatment, and prognosis of women with lung cancer during pregnancy. Methods: The clinical and pathological data of 3 pregnant women with lung cancer who were treated at our hospital were retrospectively analyzed, and the relevant literature was reviewed. Results: The three patients with lung cancer during pregnancy were all under 40 years old, and the gestational weeks of diagnosis were 20, 22 and 36 weeks, respectively. Two of the women were clinical stage IV and 1 was clinical stage III, all of which constitute advanced lung cancer. Pathological types are adenocarcinoma, small cell neuroendocrine carcinoma, and adenocarcinoma with neuroendocrine carcinoma respectively. Two patients were diagnosed during the second trimester and had mid-term induction of labor. After lung cancer surgery in other hospitals, they were died at 4 and 7 months after diagnosis. The remaining patient, who was diagnosed at 36 gestational week underwent cesarean section at 37 weeks. The patient received chemoradiotherapy, and was still alive at 19 months postpartum follow-up. Conclusions: Lung cancer during pregnancy is rare in clinic. For those who repeatedly experience respiratory symptoms during pregnancy, imaging examinations should be performed promptly, and biopsies should be taken if necessary to obtain early diagnosis. Pregnancy with lung cancer carries high risk and has a poor overall prognosis. Platinum-based combination chemotherapy is safe in the second and third trimesters.