To improve the recognition of angioimmunoblastic T-cell lymphoma (AITL) and to reduce misdiagnosis, a case diagnosed as AITL with large granular lymphocytosis was reported and the related articles were reviewed. A series of clinical tests, pathologic examination and immunohistochemical test, TCR gene rearrangement detection by multiple PCR and assay of lymphocyte immunophenotypes were carried out. The results indicated that the patient was characterized by fever, skin rash, generalized lymphadenopathy, splenomegaly, pleural effusion, ascites, anemia and thrombocytopenia, increase of circulating large granular lymphocytes with CD3(-) and CD16(+), CD56(+) were detected, T-cell receptor γ-chain gene was rearranged. More large granular lymphocytes with abnormal mitosis were found in ascites. The histological and immunohistochemical changes observed by the lymph node biopsy were compatible with AITL, some cells of which were CD56-positive. In conclusion, AITL is characterized by aggressive progress and generally occurs in elderly patients, its clinical prognosis is poor, the large granular lymphocytosis may be an autoimmune response to the tumor cells or originate from tumor stem/progenitor cells.