Cataract is one of the typical ocular manifestations of Werner's syndrome. In contrast to cataract in normal elderly persons, cataract in patients with Werner's syndrome is known to be associated with degenerative corneal changes after cataract surgery. Among the corneal changes bullous keratopathy occurs in almost 100% of patients with Werner's syndrome after cataract surgery. Although penetrating keratoplasty appears to be the best treatment for bullous keratopathy, there have been few reports on bullous keratopathy in patients with Werner's syndrome. Here we report two patients with Werner's syndrome who underwent penetrating keratoplasty for the treatment of bullous keratopathy. In both cases, visual acuity was improved, suggesting that penetrating keratoplasty is a recommendable treatment for bullous keratopathy in patients with Werner's syndrome.