The use of intrauterine devices is clearly related to a new aspect of infective pathology: bacterial contamination of the uterine cavity and its repercussions throughout the genital apparatus. Therefore the Authors decided to carry out a study of the vaginal and endocervical flora of 61 IUD users. This study has shown that pathogenic germs are present to a significant extent (82.3%) even when no clinical symptoms can be detected. The Group B streptococcus was detected in a high number of cases (10.6%) in the vaginal (9.8%) or endocervical tampon (11.5%).