A large Arab family, originating from Jerusalem, including 38 affected members (19 male and 19 female) with epidermolysis bullosa herpetiformis Dowling-Meara over four consecutive generations is described. Fourteen of 38 affected members of the family were examined clinically; their ages ranged from 2 to 35. The main clinical features were bullae, generalized, solitary, and in groups, with predilection to the skin of the palms and soles. Mild to moderate patchy hyperkeratosis of the palms and soles was found in 5 affected members of the family; their ages ranged from 2 to 7; 9 other affected adults were free. Blisters in oral mucous membranes were noted and found in summer and in periods of fever; hair, teeth, and nails were normal. Age of onset of the disease was from birth to 2 weeks. Expressivity appeared equally variable within and between sibships. Improvement was noted by progression of age from 5 to 23 years, and by some in summer and by others in winter. In contrast to previous reports, aggravation of the disease was noted during fever periods. Ultrastructural studies from a fresh blister disclosed intraepidermal blister via cytolysis of basal cell cytoplasm. The pedigree shows the transmission of an autosomal dominant gene. Affection of both consanguineous parents and their six offspring with epidermolysis bullosa herpetiformis Dowling-Meara is the most striking feature of the family--probably 25% of their offspring were homozygote.