Information on the occurrence and the mechanism of long-range transport of airborne bacteria is scarce, although Pasteur and Miquel could show that airborne bacteria were found in practically all environments. Since then there have been several symposia, monographs and reviews dealing with microorganisms in the atmosphere but only a few of these have discussed aspects of long-distance transport and in these cases fungal spores dominates. This may partly be due to the fact that long-range airborne transmission of bacteria is not regarded as a dominant health or economic problem. Instead the interest has been focused on short-range airborne transmission of medical or hygienic importance, usually indoors, as well as more basic studies on the behavior of bacterial aerosols.