Substitution of natural amino acids with their aza-amino acid counterparts in peptides has been a historically challenging prospect due to the diminished reactivity of the involved reagents. Current methods require lengthy reaction times or difficult synthetic strategies. Aza-glycine has proven to be a valuable tool in the design of triple-helix-forming collagen peptides. Herein, we describe a method for incorporation of aza-glycine in collagen peptides, and we apply the method to the synthesis of collagen peptides containing multiple aza-glycine residues.