Fermentation has been used as a food preservation method for millennia. While food safety of traditionally fermented food such as yoghurt and sauerkraut is recognised, fermentation to produce novel foods or those without a long-standing fermentation track record raises questions of food safety. Broccoli has been identified as a vegetable of interest as fermentation increases the conversion and stability of bioactive compounds in broccoli, namely the bioconversion of glucoraphanin into the bioactive compound sulforaphane. As the food safety of broccoli puree fermentation has not been ascertained, this work used challenge testing with selected foodborne pathogens (Salmonella, Escherichia coli, Listeria monocytogenes, and Bacillus cereus) to investigate the safety of this process. Broccoli was obtained from local growers and retail supermarkets. Autochthonous lactic acid bacteria, Lactiplantibacillus plantarum and Leuconostoc mesenteroides, from broccoli were inoculated as starter bacteria into 1500 g of broccoli puree (3:2 broccoli:sterile tap water) at a concentration of 108 cfu/mL. Pathogens were inoculated to achieve a concentration of 102-103 cfu/mL in the puree. Each pathogen was assessed individually, in triplicate experiments. Fermentations were conducted at 30°C for 24±2 h in stainless steel vessels until the pH was <4.0. Commencement pH was 6.5±0.1. Broccoli puree was assessed for counts of lactic acid bacteria, yeast and mould, and the pathogen of interest at commencement, after four hours and at the end of fermentation. Yeast and mould naturally present in the puree were between 103-105 cfu/mL. At the end of fermentation, yeast and mould counts were at or below the limit of detection (LOD; 10 cfu/mL). Salmonella and E. coli were also below the LOD (10 and 1 cfu/mL, respectively) at the end of fermentation. Thus, they were considered unlikely to be a food safety risk in this product. B. cereus was added at levels consistent with typical contamination in foods and remained unchanged throughout fermentation. These levels were below those expected to generate food poisoning toxins. Listeria decreased by 1-2 log10 cfu/mL but was still 101-102 cfu/mL at the end of fermentation. Listeria remains a risk and recommendations include sanitising or blanching the broccoli prior to fermentation along with end-product testing.