Introduction: Chronic lymphocytic leukemia (CLL) that arises by malignant transformation of mature B cell is the most common leukemia in elderly. CLL is characterized by accumulation of CD5(+)CD19(+) cells in the peripheral blood and lymphoid organs. While CD8(+) T lymphocytes response intracellular pathogen and tumor, CD4(+) T lymphocytes regulate immune response. T follicular (Tfol) cells stimulate affinity maturation and class-switch recombination in B lymphocytes due to cytokine and surface molecules. In this study, we aimed to investigate CD4(+)T, CD8(+)T and CD3(+)CD4(+)CXCR5(+) follicular T (Tfol) cells in the peripheral blood of the CLL patients compared to healthy controls.