In this study we present the design and synthesis of a novel class of peptidomimetics, the β^3R3-peptides. Via alternating directions of the amide bonds along β-peptide sequences, β^3R3-peptides can potentially extend the structural space available to β-peptidic foldamers. Detailed analysis at the air–water interface shows strand conformations and the formation of sheet assemblies with different degrees of crystallinity. Furthermore β^3R3-peptides exhibit a high proteolytic stability thus making them an interesting new class of peptidomimetics for biomedical applications.