Abstract The interactions between clinical and laboratory medicine moving to and from bedside, bench, and back to bedside are no more apparent than in our unraveling of von Willebrand Disease. Discovered nearly a century ago, we are still expanding both our clinical and laboratory knowledge of this disorder. There are nearly a dozen laboratory tests and as many types and subtypes of clinical von Willebrand Disease. These variables are carefully and authoritatively spelled out to include criteria for classification, which is of importance as treatment for spontaneous bleeding as well as stresses of surgery and pregnancy vary. Our increasing awareness of acquired von Willebrand Disease also provides it’s own challenges for diagnosis and therapeutics.