Periodic outbreaks of foodborne pathogens have resulted in food safety concerns, due to health implications and cost consequences. Occurrence of Listeria monocytogenes in foods and listeriosis have been reported in developed countries; however, documentation of listeriosis in South Africa is limited. In 2017–2018, Listeria was reported on polony (processed deli meat) and listeriosis was observed in South Africa (L. monocytogenes sequence type 6 (ST-6) was identified as the causal agent for listeriosis). Due to its potential effects, we conducted cost estimates to assess the implications of listeriosis outbreak with respect to illnesses, hospitalizations and deaths, and productivity losses. Cost estimates were computed on publicly available data by using USDA-ERS cost computation model for Listeria. Listeriosis had significant impacts, as mortality of 204 individuals with confirmed listeriosis cases was reported, with infants having the highest percent of fatalities (42%). The cost valuation of fatality cases was over US$ 260 million. Hospitalization costs associated with one-month recovery from listeriosis were estimated at US$ 10.4 million. Productivity losses attributed to listeriosis for humans and export value losses for food processors were in excess of US$ 15 million. Increase of food safety measures in South Africa could reduce foodborne disease outbreaks. Pre-emptive pathogen detection, sanitary procedures and bacterial inactivation can enhance control of L. monocytogenes in food processing environments. • Listeria monocytogenes occurred on polony (deli meat) in South Africa in 2017. • Costs for listeriosis were estimated using USDA-ERS cost computation for Listeria. • Listeriosis costs were quantified on hospitalization, mortality, and productivity. • Listeriosis caused 204 mortalities and fatality costs exceeded US$ 260 million. • Food safety measures would reduce disease outbreaks, human and economic costs. [ABSTRACT FROM AUTHOR]