The synthesis of the polyhalogenated phenylalanines Phe(3′,4′,5′‐Br3) (3), Phe(3′,5′‐Br2‐4′‐Cl) (4) and DL‐Phe (2′,3′,4′,5′,6′‐Br5) (9) is described. The trihalogenated phenylalanines 3 and 4 are obtained stereospecifically from Phe(4′‐NH2) by electrophilic bromination followed by Sandmeyer reaction. The most hydrophobic amino acid 9 is synthesized from pentabromobenzyl bromide and a glycine analogue by phase‐transfer catalysis. With the amino acids 4, 9, Phe(4′‐I) and D‐Phe, analogues of [1‐sarcosin]angiotensin II ([Sar1]AT) are produced for structure‐activity studies and tritium incorporation. The diastereomeric pentabromo peptides L‐ and D‐13 are separated by HPLC. and identified by catalytic dehalogenation and comparison to [Sar1]AT (10) and [Sar1, D‐Phe8]AT (14).