European Union citizens are injured each year whilst using products. Product liability law can contribute to preventing such damage by the way in which liability requirements in the context of warnings are framed and applied.Underlying these warning issues is a number of legal presumptions about how humans behave and interact with products and with their warnings. Primarily, liability law presumes that warnings can be effective in modifying user behaviour. Relative to this is the manner in which courts or litigants evaluate product warnings in European product liability law. To rule more consistently and effectively in warning issues, a solution resides in the use of guidelines in European product liability law that are based on empirical evidence on how humans interact with warnings. The author undertakes a behavioural approach towards the topic of warnings and product liability. Insights from cognitive psychology and ergonomics are essential for a thorough legal analysis of warnings as they can shed light on people's abilities and limitations with regard to processing warning information, as well as on how the design of products can contribute to preventing accidents.