The aim of this study was to investigate the mechanism, susceptibility, (18)F-FDG positron emission computerized tomography ((18)F-FDG PET/CT) features and the treatment of therapy-related acute myeloid leukemia. One patient with NHL was affected with t-MDS after treatment and then progressed to t-AML. The clinical data including bone marrow cell morphology, flow cytometry, karyotype and PET/CT features were analyzed. The results showed that the primary treatment for NHL refers to varieties of cytotoxic drug such as cyclophosphamide-hydroxydaunomycin-oncovin-prednisone (CHOP) chemotherapy. The interval time from the chemotherapy of NHL to the occurrence of t-MDS was 105 months and t-MDS progressed to AML-M(2) in 2 months. Karyotype analysis results of t-MDS and t-AML were normal. (18)F-FDG PET indicated that the FDG uptake in the bone raised diffusely. The patient showed complete response after second-line therapy (CAG regiments). In conclusion, the occurrence of t-AML/MDS may be associated with the application of the cytotoxic chemotherapeutics. (18)F-FDG PET may be an indicator predicting the transformation of t-MDS to t-AML.