Comparison of different coupling reagents for effective coupling of N-methylated, sterically hindered amino acids under solid-phase peptide synthesis (SPPS) conditions is described. Superior results were obtained with the coupling additive 1-hydroxy-7-azabenzotriazole (HOAt), as well as its uronium salt derivative (HATU), which both produced quantitative couplings. Application of these reagents to the synthesis of the 2–7 sequence found in cyclosporin is reported.