The case vignettes presented in this chapter illustrate the clinical features of patients with rare disorders of coagulation involving ADAMTS13, von Willebrand factor, and clotting factors VII, XI, XIII, combined V and VIII deficiency, and absence of all vitamin K-dependent proteins. Patients with these disorders usually note easy bruising, epistaxis, menorrhagia, hematoma formation after trivial trauma, and excessive bleeding following routine, minimally invasive procedures. Accurate diagnosis for these disorders is essential because treatment for most has become more effective and safer than simply giving fresh frozen plasma. Currently, specific clotting factor concentrates are available for replacement of factors VII, XI, and XIII as well as factors VIII, IX, X, fibrinogen, and von Willebrand factor.