Cranberry (Vaccinium macrocarpon Ait.) ingestion has long been associated with prevention of urinary tract infections. The beneficial mechanism was historically thought to be due to the fruit acids causing a bacteriostatic effect in the urine. However, recently, a group of proanthocyanidins (PACs) with A-type linkages were isolated from cranberry which exhibit bacterial antiadhesion activity against both antibiotic susceptible and resistant strains of uropathogenic P-fimbriated Escherichia coli bacteria. The link between cranberry ingestion and maintenance of urinary tract health as well as the structural diversity, pharmacokinetics, quantification, and bacterial antiadhesion bioactivity of the A-linked cranberry PACs are reviewed.