Full‐length human von Willebrand factor (vWF) cDNA was assembled from partial, overlapping vWF cDNAs. This cDNA construct includes a coding sequence of 8439 nucleotides which encode a single‐chain precursor of 2813 amino‐acid residues, representing a putative signal peptide, a prosequence and mature vWF of 22, 741 and 2050 amino acids, respectively. This represents the longest coding sequence determined to date. In‐vitro expression of full‐length vWF cDNA revealed the synthesis of a polypeptide with a mol. wt corresponding with that of the unglycosylated precursor. The precursor is a highly repetitive protein which consists of two duplicated (B, C), a triplicated (A), a quadruplicated (D) and a partly duplicated domain (D'), in the following order: H‐D1‐D2‐D'‐D3‐A1‐A2‐A3‐D4‐B1‐B2‐C1‐C2‐OH. Both the prosequence, composed of two D domains (D1, D2), and mature vWF harbor an arg‐gly‐asp (‘R‐G‐D’) sequence which has been implicated in cell‐attachment functions. It is argued that the pro‐sequence is equivalent to von Willebrand Antigen II (vW AgII).