The vasodilator-stimulated phosphoprotein (VASP) is a key regulator of actin dynamics. We have determined the 1.3-A resolution crystal structure of the 45-residue-long tetramerization domain (TD) from human VASP. This domain forms a right-handed alpha-helical coiled-coil structure with a similar degree of supercoiling as found in the widespread left-handed coiled coils with heptad repeats. The basis for the right-handed geometry of VASP TD is a 15-residue repeat in its amino acid sequence, which reveals a characteristic pattern of hydrophobic residues. Hydrophobic interactions and a network of salt bridges render VASP TD highly thermostable with a melting point of 120 degrees C.