Keratinocytes from patients with different types of epidermolysis bullosa (EB) demonstrated an abnormal tendency to blister or bleb formation after 14-22 days in culture. The changes were most marked in samples from cases of junctional EB and were not observed in control cultures of normal skin. These findings suggest the possibility of a primary abnormality of keratinocyte adhesion in different varieties of EB and that keratinocyte culture should provide a useful model for further studies on disorders of adhesion in EB.