Abstract Intensive immunosuppressive therapy (IST) can greatly improve the survival prognosis of severe aplastic anemia (SAA). Nevertheless, approximately 30% of SAA patients did not respond to initial IST treatment. For these patients, salvage treatment poses a challenge. Therefore, predicting the efficacy of IST for SAA at initial diagnosis and developing the optimal curative regimen may enhance treatment outcomes. Trisomy 8 is one of the most common cytogenetic abnormalities in myeloid neoplasms and the BCL6 corepressor (BCOR), a transcription factor, also plays a role in hematopoiesis by inhibiting differentiation toward the myeloid lineage. It is rare that trisomy 8 and BCOR mutation present simultaneously in SAA, which may predict the efficacy of IST for SAA independently. Herein, we presented a SAA patient with both trisomy 8 and BCOR mutation at diagnosis. The bone marrow (BM) aspirate showed hypocellular BM and the bone marrow biopsy revealed a severe hypocellular bone marrow (15% cellularity). The patient rapidly relieved with reduced transfusion and achieved response after IST treatment. Biopsy about 3 months following IST showed remission, and the volume of hematopoietic tissue reached 40%. BM aspirate showed improvement (Grade III). Cytogenetic analysis revealed a normal karyotype. NGS still revealed BCOR mutation, and complete blood cell count results were improved. In conclusion, we are the first to describe a rare case of SAA with both chromosome 8 abnormality and BCOR mutation in detail. Review of the literature showed that the coexistence of trisomy 8 and BCOR mutation may represent a new distinct entity in SAA.