Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B-containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against ATCC 11775, ATCC 13636, and ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against ATCC 11775 and ATCC 13076. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by .