Technical Abstract: Campylobacter is an important human pathogen and consumption of undercooked poultry and cross-contamination from raw product has been linked to significant human illnesses. To reduce human illness, intervention strategies targeting Campylobacter reduction in poultry are being developed. Researchers are leveraging Campylobacter ecology data to drive these strategies. For more than a decade there has been an ongoing national and international controversy about whether or not Campylobacter can possibly pass from one generation of poultry to the next via the fertile egg. It is recognized that there are numerous sources of Campylobacter entry into flocks of commercial poultry (including egg transmission) but a significant number of scientists have steadfastly refused to accept anything but post-hatchery environment as the source. This approach can lead to ineffective Campylobacter intervention strategies within poultry. There has been an abundance of published research in many countries of the world that refutes their contention. In this article, findings from a plethora of research studies evaluating general as well as Campylobacter vertical transmission in poultry is discussed. The article is intended to demonstrate that vertical transmission should be considered a significant source of flock Campylobacter contamination. The information should be leveraged by researchers to develop innovative intervention strategies that address both environmental and parent-to-progeny routes of Campylobacter flock contamination. The opportunity is to use this approach to drive effective reductions in flock contamination. Improvements in cultural and molecular laboratory methods will continue to advance our knowledge of Campylobacter ecology and as researchers embrace both Campylobacter routes of entry into flocks will lead to better strategies aimed at reducing/eliminating Campylobacter within poultry flocks.