Abstract: Eleven patients with pemphigus foliaceus (PF) and 8 patients with pemphigus vulgaris (PV) were studied by immunofluorescence technique: IgG and C3 deposits were found in thq: intercellular spaces (ICS) of the epidermis in all patients with PF and PV by direct immunofluorescence (DIF). 84.6% of tree pemphigus patients had anti-ICS antibodies in the sera with a titre ranging from 1:40-1:2860. 45.4% of patients with PF were found to have IgG deposits localised predominantly or solely in the ICS of the superficial epiderirtal layers by DIF, while this was not the case in patients with PV. After careful evaluation of the above findings, the authors suggest that (1) the diagnosis of pemphigus can be established if deposits of IgG are present in the ICS o the epidermis by DIF; (2) if the fluorescent staining of IgG in the ICS is more prominent in the superficial than in the deep epidermal layers by DIF (more than one +),the diagnosis of pemphigus foliaceus can be ascertained; and (3) when a high titre of anti-pemphigus autoantibody in the serum (>1:40) is present in patients with bullous dermatoses, a diagnosis of pemphigus may also be established.