"Due to the nature of their production horticultural crops are at risk of microbiological contamination from a range of sources. It is therefore imperative that growers are aware of where risks may arise on farm so that targeted interventions can be put in place to minimise transference of pathogens onto crops.  The objective of this study was to identify the areas most likely to harbour foodborne pathogens in commercial horticultural settings in Ireland. Produce, water and environmental swab samples were collected from commercial production units (n=12) for four crops, namely strawberries, carrots, lettuce and spinach, on four different occasions. Each sample was tested for the presence of Listeria monocytogenes, Salmonella spp. and Shiga toxin producing E. coli by standard methodologies.  In total 765 samples were collected, including 585 environmental swabs, 61 produce samples and 119 water samples. L. monocytogenes (n = 20 isolates) was detected in 13 samples (2.1%). Samples from seven out of the 12 sites harboured  L. monocytogenes on at least one occasion.  No Salmonella was detected in any sample .Eight enrichments from the 765 samples tested positive for stx genes but no STEC were recovered. Whole genome sequencing was utilised to compare the L. monocytogenes isolates, as well as to provide information on their serotype and virulence gene properties. This study indicated that the horticultural production and processing environment can harbour L. monocytogenes, particularly on surfaces, and therefore particular emphasis should be placed on rigorous cleaning and disinfection and minimising cross contamination of the crop."