Background: Chemotherapy and radiotherapy used in cancer treatment are associated with increased risk of secondary myelodysplastic syndrome (MDS). MDS is characterized with specific chromosomal abnormalities and genomic alterations in JAK2, KRAS, CBL, DNMT3A, TET2, IDH1/2, EVI1, RUNX1, GATA2, EZH2, ASXL1, SF3B1, U2AF1, SRSF2 and ZRSR2. Since next generation sequencing (NGS) techniques have been widely used for the detection of actionable genomic variation in solid tumor patients, analysis of NGS data for chromosomal abnormalities and gene mutations may be supplementary for diagnosis of secondary MDS. Methods: We retrospectively analyzed targeted NGS data of paired tumor and blood samples from patients with non-small cell lung cancer (NSCLC) for chromosomal abnormalities and gene mutations. Sequence panel covered whole exons of 381 genes associated with cancers. Sequence data were processed using a customized analysis pipeline designed to accurately detect multiple classes of genomic alterations in routine clinical specimens. All testing was done in a CLIA-certified, CAP-accredited laboratory. Clinical information of cases with chromosomal abnormalities was reviewed, including treatment for previous cancer, blood and bone marrow tests. Results: We found 4 cases carrying MDS associated chromosome abnormalities among 3523 NSCLC patients with the prevalence of0.1%. They were old (from 66 to 71 years old), and were more likely to be male (3 males and 1 females). All of 4 cases included common abnormalities associated with MDS like 5q-, 7q-, -7, +21. 3 cases had complex (≥3) abnormalities and 1 case had double abnormalities. Point mutations were identified in blood samples of 3 cases. Mutations in TP53 occurred in 3 cases, mutations in ASXL1, DNMT3A, FLT3 and CBL occurred in one case respectively. Among the 4 cases, 2 cases were confirmed as MDS by blood and bone marrow tests. Conclusions: We identified 4 MDS associated chromosomal abnormalities from 3523 NSCLC patients through analyzing NGS data. NGS techniques could serve as supplementary for diagnosis of secondary MDS.