Coagulation factors, anticoagulants, and fibrinolytic proteins are important for hemostasis, and mutations affecting these proteins causes some rare inherited bleeding disorders that are particularly challenging to diagnose. This review provides current information on rare inherited bleeding disorders that are difficult to diagnose. A review of the literature was conducted for up to date information on rare and difficult to diagnose bleeding disorders. […] Some rare bleeding disorders cause an inherited deficiency of multiple coagulation factors (F), such as combined FV and FVIII deficiency and familial vitamin K-dependent clotting factor deficiency. Additionally, congenital disorders of glycosylation can affect a variety of procoagulant and anticoagulant proteins and also platelets.