Syntheses of highly mannosylated polyester dendrimers with 2, 4, 8, and 16 α-D-mannopyranose residues on their peripheries connected by different linker arms are presented. Attractive features of these systems as potential inhibitors of uropathogenic Escherichia coli (UPEC) include the use of nontoxic and biocompatible polyester dendrimer backbones, aglycones whose lengths are designed to fit in the tyrosine gate, and multiple copies of α-linked D-mannopyranose residues, capable of effectively binding to the exposed mannose-sensitive type 1 pili on UPEC's outer surface.