The commercial hybrid males with clinically normal reproductive potential, from two rabbitries with different hygienic standards, have been tested over six weeks obtaining 89 ejaculates. Semen was collected twice a week using an artificial vagina, with or without changing the sheath at every collection. The semen was promptly diluted in sterile tubes and used for A.I.. The first and the last doses of the ejaculates were packed in paillettes and stored under liquid nitrogen. Our cultures of the frozen rabbits semen revealed a variety, both of quality and quantity, of microbial contamination. Escherichia coli, Staphyloccus aureus, Clostridium perfringens were found in 8% to 46% of the samples. Pasteurella spp., Enterococcus spp., Pseudomonas spp., Bacillus spp. and Proteus spp. were sporadically present. The count differed between rabbitries and according to the method of semen collection. The differences were not statistically significant. The bacterial contaminants had little effect on fertility, nevertheless collection and processing of rabbit semen should always be done in such a way as to minimize contamination by microbiological agents