The glycoprotein (GP)Ib-IX-V complex is the platelet receptor for von Willebrand factor and many other molecules critically involved in he most as is and thrombosis. The lack of functional GPIb-IX-V complexes on the platelet surface is the cause of Bernard-Soulier syndrome, a rare hereditary bleeding disorder also associated with macro thrombocytopenia. The GPIb-IX-V complex contains GPIbα, GPIbβ, GPIX and GPV subunits, all of which are type I trans membrane proteins containing leucine-rich repeat domains. Although all the subunits were identified decades ago, not until recently did the mechanism of complex assembly begin to emerge from a systematic characterization of inter-subunit interactions. This review summarizes forces driving the assembly of the GPIb-IX-V complex, discusses their implication on the pathogenesis of Bernard-Soulier syndrome, and identifies questions that remain about the structure and organization of GPIb-IX-V.