Lyme disease or Lyme borreliosis is the most prevalent tick-borne disease in America. The etiological agent of Lyme disease is the Borrelia spirochete. Transmission of Lyme disease in North America is through the deer tick, which take blood meals from infected white tailed deer. The hypothesis of this study is that Lipotena cervi (ked flies), which also take blood meals from the white tail deer, carry this bacteria. PCR analysis was used to detect the presence of the B. burgdorferi flagellin B (flaB) gene in DNA from ked flies. Of 40 ked flies tested, 8 were positive for the flaB gene, yielding an infection rate (20%) that is very similar to that found in ticks taken from the regional deer population (25%). Gel electrophoresis showed that the PCR product was approximately 30 base pairs smaller than the predicted size for B. burgdorferi. This is also consistent with variation in the flaB gene among strains of this bacteria and may indicate a unique strain of B. burgdorferi in ked flies. It is possible that the strain of Borrelia cycling in ked flies may be different from that in regional deer tick populations.