Improper food handling practices can cause food contamination. Food safety knowledge and training alone cannot be effective enough to change food handlers' hygiene behavior in practice. Employees’ behavior is significantly influenced by various factors at the individual and organizational levels. Nudge tools in food businesses are not well researched, but they could have an important impact on improving employee hygiene behaviour. The aim of this study was to assess the impact of nudge tools on behavioural change in food handlers’ hygiene behaviour in selected kitchens of educational institutions. We used a qualitative research methodology (five-stage semi-concealed observation of food processing employees' hygiene behaviour, design of a visual nudge tool with short text). The sample consisted of 11 employees in two kitchens at the same educational institution. The results were presented as compliance rate (%) of hygiene behaviour. Compliance with hand washing techniques increased with the use of nudge tools. The greatest improvement was achieved with the combination of citrus sense and text (up to 38%). Adherence to hand washing techniques was different in Kitchen A and Kitchen B. When using the image of a man's eyes or the combination of citrus sense and text, compliance with avoiding hand contact with ready-to-eat food was up to 65%. The nudge tools influenced the hygiene behaviour of the food handlers in the kitchens observed, but the efficiency of the different nudge tools was not the same.