Hospital-care-associated infections (HCAIs) represent the most frequent adverse event during care delivery, affecting hundreds of millions of patients around the world. Implementing and ensuring conformity to standard precautions, particularly best hand hygiene practices, is regarded as one of the most important and cheapest strategies for preventing HCAIs. The behavioural sciences have documented the potential of adjusting seemingly irrelevant contextual features in order to ‘nudge’ people to conform to desirable behaviours such as hand hygiene compliance (HHC). In this field experiment we investigate the effect on HHC amongst visitors upon entry of a hospital by varying such features.