Two brothers with pachydermoperiostosis, an autosomal dominant syndrome characterized by digital clubbing, periosteal new bone formation, coarse facial features with thick, furrowed, and oily skin, presented in their twenties with severe complicated duodenal ulcer disease requiring multiple operations. Their father and one paternal uncle also had pachydermoperiostosis and a past history of ulcer dyspepsia. The mother, one sister, two maternal aunts, and one other paternal uncle were healthy. Both brothers had giant hypertrophic gastritis (Ménétrier's disease). Their pentagastrin-stimulated acid output and fasting and meal-stimulated serum gastrin levels were normal, but their serum pepsinogen I and II levels were markedly elevated. The father had hypochlorhydria and a low serum pepsinogen I/II ratio, suggesting atrophic gastritis. This family study raises the possibility that pachydermoperiostosis, hypertrophic gastropathy, and peptic ulcer may be genetically related.