ABSTRACTAntibody against human lysozyme was purified from sera of immunized rabbits using the immuno‐absorption technique.After conjugation of the purified antibody against human lysozyme with fluorescein isothiocyanate (FITC), immunofluorescent studies were carried out on both normal human skin and peripheral blood cells. Specific immunofluorescence appeared in the cytoplasm of epidermal cells and was much stronger in the upper cell layer than in the basal cell layer. Only slight fluorescence appeared in the horny layer. In the dermis, linear fluorescence was found along collagen fibers. In the immunocytological examination of peripheral blood cells, lysozyme was found in the cytoplasm of the polymorphonuclear leucocytes (PMN's