To facilitate the preparation of beta-peptide libraries in parallel, we have adapted reaction conditions for the solid-phase synthesis of 14-helical beta-peptides for use in a multimode microwave reactor. The low temperature/pressure requirements of microwave-assisted beta-peptide synthesis were found to be compatible with multiwell filter plates composed of polypropylene. Microwave heating of the 96-well plate was sufficiently homogeneous to allow the rapid preparation of a beta-peptide library in acceptable purity.