Giving the rising interest in peptidomimetics and peptides in different biomedical fields, a new optimized and fast protocol for the synthesis of such compounds is increasingly in demand. Thus, a seven-step protocol for the synthesis of a dimeric polymyxin-inspired peptidomimetics is reported here. The protocol consists of two solid phase peptide synthesis (SPPS) steps, both followed by an in-solution cyclization reaction. Then, a click reaction and Fmoc deprotection were performed before the final coupling and global deprotection. This protocol has been optimized for the synthesis of polymyxin-like peptidomimetics, but it can be applied also for the synthesis of several kinds of peptides and peptidomimetics.