We studied the histopathologic, ultrastructural, and immunopathologic characteristics of conjunctiva from patients with Stevens-Johnson syndrome (SJS). A small subset of SJS patients with recurrent conjunctival inflammation unassociated with external factors such as lid margin keratinization, sicca syndrome, trichiasis, or entropion was identified. The ultrastructural and immunopathologic characteristics of the conjunctiva from these patients were distinctly different from those of the conjunctiva from SJS patients without recurrent conjunctivitis, and suggested an active, immunological mediated inflammation. Vasculitis or perivasculitis, immunoreactant deposition in vessel walls, vascular basement membrane disruption, thickening, and reduplication, and a preponderance of helper T-lymphocytes, macrophages, and Langerhans’ cells were the notable distinguishing features in those patients with recurrent conjunctival inflammation. This rare clinical syndrome may represent the ocular counterpart of recurrent dermal or oral mucosal erythema multiforme.