In this communication, we report the design, synthesis and in vitro antimicrobial activity of ultra short peptidomimetics. Besides producing promising antibacterial activities against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), the dipeptidomimetics exhibited high antifungal activity against C. neoformans with IC₅₀ values in the range of 0.16–19 μg mL⁻¹. The most potent analogs exhibited 4-fold higher activity than the currently used drug amphotericin B, with no apparent cytotoxicity in a panel of mammalian cell lines.