Mantle cell lymphoma (MCL) is a rare group of non-Hodgkin's lymphoma (NHL), which is difficult to discriminate from other subtype of small lymphocytic lymphoma in morphologic appearance. In order to enhance the understanding of MCL, a case of MCL first diagnosed as follicular lymphoma (FL) was reported. The clinical and laboratory characteristics of MCL were analyzed and summarized. The results showed that the findings of flow cytometry (FCM) and immunohistochemical staining technique were compatible with the diagnosis of MCL. Cytogenetic analysis can detect multiple types of chromosomal abnormalities, including t (11; 14). In conclusion, MCL is a disease which diagnosis is difficulty confirmed. Interphase fluorescence in situ hybridization, multiplex fluorescence in situ hybridization, FCM and immunohistochemical staining technique play important roles in the diagnosis of MCL.