Human blood contains a memory counterpart of T follicular helper (T(FH)) cells. Blood T(FH) cells are composed of subsets that differ in phenotype and function. Recent studies show that analysis of blood circulating memory T(FH) cells can provide clues to understand the mode of actions of vaccines and the pathogenesis of human autoimmune diseases. We will describe here a detailed protocol to analyze the memory T(FH) subsets in human whole blood samples. We will also describe a protocol to assess the helper capacity of blood memory T(FH) subsets.