Phage peptide display technology was used to identify peptides that bind specifically to the amyloid form of the A.beta..sub.1-40 peptide. Peptides with similar structural features and bind to the amyloid form of A.beta..sub.1-40 but not to monomeric A.beta..sub.1-40, are provided. Such peptides are useful as carrier molecules to deliver therapeutic and diagnostic reagents to amyloid plaques.