According to the World Health Organisation (WHO), globally 600 million people suffer from food-borne diseases (FBD), and 420,000 people die as a result. The European Food Safety Authority (EFSA) has stated that FBD are linked to the food industry, with the most common means of transmission being due to poor food handling and hygiene by food handlers working in the food industry. The aim of this research was to investigate the effectiveness of mandatory food handler training programmes (FHTP) to prevent FBD in Malaysia and Ireland. To do this, the FHTP existing in Malaysia and Ireland were analysed, in addition to the legislation they fall under in each respective country. Effectiveness was determined by investigating the level of food safety knowledge (FSK) and food safety practices (FSP) of food handlers in Malaysia and Ireland. A systematic literature review (SLR) and a narrative literature review (NLR) were conducted for this research. The SLR was based on the PRISMA diagram, using the Confidence in the Evidence from Reviews of Qualitative research (CERQual) approach to evaluate the studies used for this research. A total of 8 Malaysian studies and 1 Irish study were used to determine the level of FSK and FSP of food handlers in each respective country, to examine the effectiveness of FHTP. The results of the studies used for this research have depicted overall good FSP and FSK of food handlers in Malaysia and Ireland; yet trends continue to show that food handlers are one of the biggest contributors to FBD, demonstrating that FHTP are not effective in preventing FBD. The findings from this research highlights that although these trainings can be an effective tool to prevent FBD, if they are not executed correctly, food handlers will continue to contribute to FBD.