The bacterial flora of the preputial space of 210 healthy males (43 children aged between 2 and 11 years, 137 males between 12 and 60 years and 30 men over 60 years) was determined by smears and cultueres from glans penis, sulcus coronarius and the adjacent prepuce. The results were grouped according to various criteria, e.g. glans covered or uncovered and age of males. Differences in the distribution of germs could be found in relationship to age. In the case of an uncovered glans penis the presence of microbial flora corresponds to the grampositive saprophytic bacteria in areas rich in sebaceous glands. In the case of a covered glans the density of microorganisms increases. Prevalent are gramnegative anaerobes, especially Bacterioides melaninogenicus, also enterococci, enterobacteria and coagulase-positive staphylococci.