A terminally protected acyclic tetrapeptide Boc-Aib-Val-Aib-β-Ala-OMe 1 (Aib: α-aminoisobutyric acid, β-Ala: β-Alanine) self-assembles into a continuous hydrogen-bonded supramolecular helix with an average diameter of 10Å (1nm) starting from a double bend molecular conformation in crystals and further self-assembly of this supramolecular architecture leads to the formation of polydisperse nanorods of diameters 10–40 nm.