Over the past 12 years, we have been collecting a variety of samples during health assessment sessions in order to characterize the microbiology of free-ranging bottlenose dolphins. During 1990-2002 we sampled free-ranging bottlenose dolphins off Florida, Texas, and North Carolina. Blowhole and anal/fecal samples yielded 1,871 bacteria and yeast isolates including 85 different species or groups of organisms. The following represented >50% of organisms recovered: vibrios, unidentified pseudomonads, Escherichia coli, Staphylococcus  spp., and a large group of nonfermenting Gram negative bacteria. Vibrio alginolyticus and Vibrio damsela  were the most commonly recovered bacteria and were dominant in both anal/fecal and blowhole samples. Many organisms occurred sporadically in dolphins sampled repeatedly, but some were regularly associated with a given individual and may indicate a carrier state. Vibrios were common, but some geographic variability in the presence of these and other organisms was noted. Potential pathogens of humans and other animals were recovered. These could be transmitted from animal to animal and thus distributed in different environments by transient dolphins, with subsequent health implications. Progress has continued on the establishment of the normal microbiological flora of wild dolphins. Eight animals from Sarasota Bay were examined in Feb. 2005 and, in a comparative study, 11 dolphins from St. Joseph Bay in the Florida panhandle were studied. These on-going studies are providing us with an emerging and, we believe, important inventory of the microflora of normal healthy animals. Comparisons can then be made with microorganisms recovered from stranded dead and alive animals. Appropriate treatment can then be applied to the latter for improved conservation practices.