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.